NetworkToolbox news

Update your Google privacy settings

This is a reminder to double-check your Google privacy settings again because Google has recently automatically re-enabled some privacy settings you may already have turned off some time ago.

Google continues to ignores our will and do everything they can to collect our data and jeopardize our privacy.

For this reason, better login to your Google account, click the new privacy link at the bottom and double-check all privacy settings and don’t forget to logout of your account at the end.

And while you are caring for Google Privacy, why not also double-check your other privacy settings on Facebook, your Microsoft account or other social media accounts.

Stay save and secure!


NetworkToolbox news

About Pegasus

In case you have not yet heard about Pegasus. Pegasus is a spyware developed by an israeli company called NSO who claim they sell this spyware only to authorized governments.

Findings of Amnesty International uncovered that Pegasus has been (and likely still is) widely used against all kind of people.

It is no surprise that Pegasus was easy to spread on Android phones, since they do not have essential security measures. However, it was as easy even on iOS devices which was indeed surprising.

This was possible by using an iMessage exploit. It was possible to send invisible iMessage to iPhones to install the spyware without the knowledge of the owner and simply by knowing the iPhones’s mobile phone number.

This was indeed really scary.

The good news is that this issue had been fixed in iOS 14.7. So if you have not yet updated, better update your iPhone or iPad right now!

You are probably wondering now how to find out if you are affected by Pegasus. Unfortunately, there is no easy way to do this.

I gathered every information which is available about Pegasus and even analyzed an iPhone which was infected myself. Unfortunately, I can’t find a reliable way to identify a possible infection from within Network Toolbox and if it’s not reliable I can’t provide a Tool or kind of security scan for Pegasus. Even though a few artifacts could be identified by my App the results would never be reliable enough.

However, if you are experienced enough and like to see if Pegasus is installed on your device, fortunately, People from Amnesty International have developed a Toolkit for this. You can find this Toolkit here:

The basic procedure is to create a Backup of your device and let the Toolkit scan this backup for artifacts of Pegasus. Another option (instead of creating a Backup) is to jailbreak your device for the scan but I won’t recommend that method of course.

Stay safe and don’t trust the evil,


P.S. I am already working on the next update of Network Toolbox

NetworkToolbox news

Are you one of the half billion People who got Facebooked?

Facebook did a bad job protecting your data. Records of more than half a billion users got lost and can now be downloaded by everybody.

The records contain phone numbers, Facebook ID, Facebook name, gender and sometimes additional information like email address, relationship status, dates and location of birth and more.

Facebook as usual downplayed the data breach and don’t even see any reason for informing the affected users.

But now, you can use my App to find out if your phone number is contained in the breached data.

This incident is again a good reason why it is no good idea to let Facebook join the data of your Facebook account and WhatsApp but it is now probably too late for many users. Bad guys have already started to use the leaked data to send malicious Text messages or emails.

To check if your phone number is included in this huge Facebook data breach, just use the included Pwned Tool and enter the phone number you like to check in international format (e.g. +16506447386).

By the way, this is the phone number of a person named Mark Zuckerberg, Facebook ID 4 which is also included in the breach. I am wondering if I should give him a ring?

However, maybe it’s time to leave Facebook. I did already some time ago.

Don’t trust the evil – especially not Facebook ID 4!

Stay safe,


NetworkToolbox news

Oops, they did it again – Zyxel again with hard-coded Backdoor

If one made a mistake, that’s bad but may happen. If one made a mistake twice, there is no excuse.

Zyxel did it again. They placed a fixed username password (zyfwp/PrOw!aN_fXp) backdoor in their most sensitive firewall and VPN products.

In late 2016, Zyxel has been caught for using a hard-coded superuser (su) backdoor password (zyad5001) in their products.

One would usually think that Zyxel would learn from this inexcusable and unacceptable mistake and that buyers would avoid Zyxel in the future.

None of this has happened. Zyxel is selling their devices and appliances like crazy and – believe it or not – they hard coded again a backdoor into their products.This backdoor was found in their Firewalls and VPN Gateways (ATP – Advanced Thread Protection, USB Unified Security Gateway, USG Flex, VPN and NXC WLAN Access Point series).

Thousands of these devices are exposed to the internet and easy to discover by the included Shodan Tool of my App.

A huge number of them are still unpatched and can be accessed using the backdoor credentials and several of them have already been compromised by ransomware.

Hard-coding passwords is one of the silliest things developers can do – not only but especially for security products. If Zyxel developers (and QA department) are that stupid, how can one ever trust in their products again? Especially after this now happened twice. Make your own opinion.

You all have a good and safe start into the new year 2021 – and stay healthy.



NetworkToolbox news

A new Packet Tool has been added

The latest update of NetworkToolbox received a new Tool called Packet.

I implemented this Tool while I needed to monitor traffic from a Software that sends UDP packets to another software. For both programs it was possible to enter the IP Address and the Port where the UDP traffic should be sent to or come from. So the only thing I needed was a Tool that behaves like a server which waits for network traffic on a certain port and displays it.

Once that Tool was finished and did do it’s job, I added the possibility to not only display received packets but also be able to send packets and not only to use the UDP protocol but also the TCP protocol and this is now how it looks like:

In the upper part “Transmit:” you can enter the destination address, port number and select the protocol (UDP or TCP). Below you can enter the data which should be sent (in this case the text “test”) which is repeated 1 time. If you tap on HEX the text will be converted to hexadecimal digits and you can continue to enter more hexadecimal digits.

(Note: if you want to send a packet of 256 bytes of zeros, you can enter 00 in Hexadecimal and 256 for Repeat)

If you tap on Send, that data will be sent immediately and further below, at the bottom, you will see the result which might be an error if you have selected TCP and if on the given IP Address and port, no server is waiting and accepting the data.

In the “Receive:” section of this Tool, for your convenience, you will see the IP Address of your device (which is where this Tool is listening for the data). Below, you can enter the Port where to listen and you can select again if you like to use the UDP or TCP protocol. Once you tap on “Start Listen” the Tool will start a Server process that is listening on the given port and protocol.

In the example above, I did use the same IP Address, port and protocol for sending and receiving so once I sent a packet, it will be received and displayed in list at the bottom (in opposite order, newest first).

There are many use cases for such a Tool. If you have two iOS devices, you can use one for sending, the other for receiving and can check if data on a certain port will pass through, even from inside your network or outside to inside.

Or you can send wrongly formatted or too large packets to see if a server still behaves correct after receiving such packets.

Or, like in my case, where I wanted to understand the UDP data which was sent by a Software. After finishing this Tool, I was also able to modify the data and send it to the original destination software using the “Transmit:” part of this Tool. For this, I did conveniently use the “Copy RX data” button, pasted this data from the clipboard in the “Data:” field and modified it.

Regarding UDP and TCP

Some of you might wonder about TCP and UDP and the difference between those two. The definitions for these abbreviations are explained in the Glossary of this App.

But in short, you can see both protocols as a standard to transfer data between two network services. The difference is, that TCP requires an established connection for the transmission whereas UDP does not. So TCP is more robust and you always know whether or not the data has been transferred which is not the case for UDP. However, TCP has more data overhead and is slower than UDP. TCP is being used for website traffic wheras UDP is being used for Audio and Video traffic where lost packets are not that important.

I hope you will find this new Packet Tool useful.

Please don’t forget to rate my App which helps to keep it going.

Thank you all and stay safe.


(As a reminder, new Tools are always appended at the end of the Icons and may have wrapped to another page. If you like to reorder the Icons, just head to Settings → Appearance → Organizer. From here you can either sort the Tools manually or select […] reset to defaults and all Tools will be re-sorted in a way that similar Tools are grouped together)

NetworkToolbox news

About VPN – be careful what you do

VPN is a buzzword, used for different things, sometimes for something which is the complete opposite.

Most people think of increased protection or privacy in connection with VPNs.

That is not fully true and, in some cases, (read further below) you can instead jeopardize your security and privacy when using a VPN.

I am personally using a VPN almost whenever I am outside my home. I am using it regardless of whether I want to connect to my devices at home or any other website or server. This way, I can use virtually any WiFi hotspot without risking a Man-in-the-Middle (MITM) attack or other common issues like tracing by browsing activities etc. Moreover, I can benefit from my Pi-Hole installation (see here for more about Pi-Hole) from any location so I can enjoy ad-free and faster browsing.

Evil VPNs

However, some people are using so called “VPN” Apps or VPN providers. DON’T DO THAT!

Recently, it was revealed that several of these Apps and services are spying their users out. Very popular names are on a list of Apps that have been identified to track their users, possibly to make money by selling this information. As I used to say, “don’t trust the evil”.

You may ask, which VPN App or service I would recommend? The answer is simple: None of them.

But why? And what is the difference between those and “my” VPN.

The thing is, I would not even call those solutions a “VPN” because “VPN” stands for Virtual Private Network. These solutions might be virtual and a network, but they are by no means private because your data is routed through their servers and at any point, technically, they have access to your data. You will never know if they respect your privacy or (as it happened) tapping into your data. And if you would trust a VPN provider today, can you trust them in the future? After they found they are not making enough money and are looking for additional opportunities. Some of these providers are even free of charge. How crazy is that? How can one maintain a secure infrastructure for people around the world and give it away for free? There is probably something they don’t tell you.

So should you rather omit any VPN? No, just use the right one and the right one needs to be your own, private VPN. It is essential that the starting point of the encryption and the endpoint is under your control.

A typical VPN is “tunneling” your data over the line. Tunneling means you data can’t go any other than the predefined route and it is usually encrypted from the beginning (of the tunnel – which is the device from where you want to access the network) and decrypted not sooner than at the end (of the tunnel – which is where it goes back to the public or ideally the destination server).

Corporate VPNs

VPNs can be used between your device and the destination network. This is, what companies are using (or I should rather say have to use) for their employees if they want to give their employees access to the company infrastructure like mail, access to files etc. while they are not located inside the company. For example, if they are working from home. Of course, this is getting more popular these days due to Covid-19. In these cases, the tunnel goes from the PC or mobile device of the employee up to the company’s network. Regardless which internet provider is being used or if the employee is working from a Hotel or insecure WiFi in a coffee shop. Such a solution is secure.

VPNs to access a Server

The very same solution can be used if you want to securely connect from your home network to another server on the internet. I am using that whenever I am maintaining my Servers around the world.

Home VPN – my recommentation

But such a solution is also viable for home networks. If the tunnel would start on your mobile device and would end on your network at home, you could benefit from the much higher protection degree of your home network (which is hopefully under your control) even if you are on the road and using any (probably insecure) network.

And that’s exactly what I would suggest to everybody. Setup or use your own VPN and don’t rely on or trust anybody outside your network.

Of course, this needs a bit extra work and at least some networking knowledge but it’s not as complicated as you may think. And it’s really worth to dig into this. Once you set it up, you don’t want to miss it anymore. Especially if you are also using Pi-Hole.

I can suggest at least two possibilities.

VPN on a Raspberry Pi

One would be to buy a cheap Raspbarry pi and use it as VPN server. Better use a separate one which will solely run the VPN. There are several instructions available on the web, especially for installing a VPN on a Rasperry pi. Just use your favorite search engine and look for instructions that best suits your skills and requirements. My favorite VPN software is Softether. I am not fond of the old OpenVPN and the new WireGuard technology, but both are better than nothing. At least WireGuard might be worth a try. But I personally don’t like VPN solutions that require an App or additional software on your device because chances are, that this software might have a security vulnerability.

When setting up a VPN, normally you can decide between different VPN technologies to be used. My recommendation is to use L2TP with IPSec which is very secure and doesn’t require an App on your mobile device because it is natively supported by iOS (and Windows and Android – by the way).

“L2TP” is the name of the technology for the Tunnel and “IPSec” the name of the technology for the encryption. There are others but for the aforementioned reason I would recommend L2TP/IPSec. However, by no means use PPTP instead because that’s outdated and insecure.

So the basic steps are:

  • Install the piece of Software (e.g. Softether) on a Raspberry pi
  • Open the necessary ports (and only those) in your router so that it lets traffic of these ports pass through to your Raspberry pi (usually these ports are 500 and 4500 for UDP traffic).
  • Configure the VPN on your mobile device

While talking about ports: If you currently have additional ports open because you want to access your NAS or Camera from outside your home, you can now close these ports because in the future you will not need them anymore because once you switch on you VPN on your mobile device, it’s like if you would sit at home, inside your home network.

Or use a device with built-in VPN Server

So this is one possibility. The other possibility, if you don’t want to (I say “want to” because you definitely can, believe me) setup a VPN on a Raspberry pi, you can see if your Router or any other device on your network offers a VPN feature. Some Routers do. If not, you can even buy and attach an additional Router just for the purpose of a VPN. However, and that’s why this is not my preference, you never know how good their VPN Server implementation is and if it is being updated timely. Often they also “just” offer openVPN but it’s probably worth an investigation.

Give it a try!

So I really recommend to give it a try. You will not regret it.

But still you might say: wait, what about watching Streaming videos that are not offered in my country and what about my privacy?

Yes, these are two things that might have been another reason why people are using a so called VPN Service. But again, this has nothing to do with privacy but both can not be accomplished by a home VPN as described before.

If you want to hide your identity on the Web, better use Tor with a Tor Browser.

If you really have to watch streaming videos that are not available in your country, better use one of those browser plugin based solutions – but ideally use it on a separate PC because even plugins can be harmful.

Looking forward to your feedback.

Stay safe and healthy – and, don’t trust the evil.


NetworkToolbox news

Best security and privacy solution

I am wondering, how many of you are already using a Pi-hole server or have installed a Pi-hole server as described in a previous blog here.

For those, who have not or don’t want to read my TL/DR, here is a quick summary:

  • Pi-hole is a solution that dramatically reduces spying of your privacy and security
  • It blocks Ads on your network
  • It works on any network for any PC (Mac or Windows) and even all Apps on your mobile devices
  • It helps to see what's going on on your network
  • It is easy to install without much network expertise
  • It just needs to be attached to your network with a regular network cable
  • It is free, OpenSource and you only need a small cheap ($ 40) Raspberry-Pi mini computer
  • It speeds up internet access
  • You can easily block unwanted connections or traffic
  • If there is any issue, it's easy to revert back
  • It is supported by NetworkToolbox

There are other solutions available with higher costs, even recurring costs but they are not better.

I personally don’t want to miss Pi-hole anymore.

So again, let me know what you think. Are you as happy about Pi-hole as I am ? Or do you think you don’t need it ? Or is it too complicated to install or is my instruction too complicated ? Or don’t you trust the Pi-hole guys?

Just drop me a mail using the form on my website or use the support button inside the App.

Keep safe,

and don’t trust the evil.



NetworkToolbox news

What a drama !

Yesterday, soon after the 12.9.3 update was finally released by Apple after several days and some unfortunate discussions about HealthKit and the Sensor Tool, I received reports from users where the App didn’t start anymore after downloading the update.

By that time, I had no idea why this happens since many users reported successful installations and also my testing on several devices and different iOS Versions didn’t reveal any issues.

Around 9pm it got obvious that at leaset several, but not all, older iOS Versions before and until 12.1. were affected. On the iOS Simulator, where I usually test everything on different iOS Versions, everything was fine.

So I started looking into my drawer to find an iPhone or iPad with an old enough but not too old iOS Version and finally found an iPhone 6 plus with iOS 12.1. After charging the completely empty device, I luckily was able to reproduce this issue.

Usually, once it’s possible to reproduce an issue it is immediately solved but not in this case. The App didn’t even start so there was no chance for debugging. It was clear that it has to do with Swift (the development language) because a certain Swift library could not be loaded. I was wondering if older iOS Versions didn’t support the version of Swift but that should not be an issue.

I tried everything like removing code that I recently added, restored and tried older code etc., nothing helped.

Then I tried to run the latest update of my Electronic Toolbox App on that iPhone 6 plus because Electronic Toolbox has received similar changes recently and to my surprise (and relief) it ran.

So I started looking for differences and after some time, I found the reason. It was a minor compiler setting out of hundreds of other settings which was the root cause. This setting will normally never be touched by a developer since it’s set correct by the Development environment automatically. For some reason it was now set in a way to let the App crash on older iOS Versions. It even has nothing to to with the error or with iOS Versions. However, once I changed that setting, the App ran on the iOS 12.1 device.

Around 2am I sent another Update to Apple. After that, I contacted Apple and explained the situation and asked for an expedite review.

This morning at 11:30am Apple indeed started their review but…

..rejected the App and claimed that it is marked as App that uses Bluetooth LE but the App is no Bluetooth LE App. I was able to sort this out with Apple and on 11:52am they released the update 12.9.5.

Sorry guys for this issue and the trouble you have had and thanks for your patience. Thanks also to Apple for their quick response.

To be honest, I don’t need that every day.



NetworkToolbox news

Block everything evil using Pi-hole

Until recently I was using my own solution to block Trackers, Ads and other unwanted network traffic. My solution works pretty well for years. Now I have replaced it by Pi-hole which is an open-source software which can run nicely on a cheap Raspberry Pi.

Pi-hole is easy to install, easy to use and offers a great user interface that gives you a great overview of what’s going on on your network and easy black- and whitelist maintenance.

Pi-hole also offers an API which will be integrated in NetworkToolbox soon.

I have created a small tutorial on how to install Pi-Hole on a Raspberry Pi.

NetworkToolbox news

Office 365 private data collection

Microsoft has not yet learned their lessons. They still can’t stop collecting private data whenever they can.

I am using Office 365 for several years and reasons (lack of alternatives). Office 365 will be updated in the background and often I didn’t noticed that it has been updated a couple of times.

With one of these latest updates, Microsoft seemed to have added some new features (from their point of view).

They have added features that are “analyzing my content“. When I read this, I had to read it twice because I couldn’t believe what I read:

You will find this option (intentionally hidden) as follows:

  • Start Word
  • On the left side at the bottom of the screen select Options
  • On the new screen select “Trust Center”
  • Click on “Trust Center Settings…”
  • Select “Privacy Options”
  • Click on “Privacy Settings”

(quite hidden, isn’t it?)

Now, it’s up to you to keep everything enabled or disable everything – which is what I did.

But be aware: Microsoft will strip down the functionality once you do that (see the yellow box below the setting) and I was wondering if I will get some money back due to the fact that they remove features they were advertising – probably not.

Don’t trust the evil!



NetworkToolbox news

WiFi Finder App collected WiFi Passwords

I still get requests from users to add a WiFi scanning tool to my App. My Answer is always that this is not possible for any App because Apple restricts access to the WiFi interface – which is good. (See also wifi-scanning)

What could happen if unrestricted access to the WiFi interface would be possible can be seen recently in an incident on Android.

A quite popular “WiFi Finder” app has collected private WiFi passwords. Those Passwords were stored as plain text along with SSID, Geolocation on a server maintained by the Chinese App developer. Even worse, that information left exposed and unprotected, allowing anyone to access and download the contents in bulk.

The App has already been banned from the Google Play Store and the Server was shut down.

Don’t trust the evil!

Best regards,


NetworkToolbox news

Spyware detection and dial codes

Before talking about Spyware detection, a few words about Spyware in general.

If you are using at least iOS 10, Spyware can only be installed on Apple devices by somebody having physical access to the device and it requires quite some time to install the Spyware and requires the device to be jailbroken. The newest iOS Version (at the time of this writing it’s iOS 12.1) can not be jailbroken at all.

There are other Spying possibilities e.g. based on iCloud Access but that’s another subject and simply changing the App ID password will prevent that.

So if you are using iOS 12.1 you can ignore the following because there can’t be Spyware on your device.

I have already written about how to detect if your device is jailbroken but again, that’s impossible if using iOS 12.1 but here are some additional tests which can easily be performed:

1.) Dial Codes

Some Spyware programs are using dial codes, to open the Spyware user interface. The following list contains known dial codes of the most common spyware software:

*#900900900 Opens the FlexiSpy uninstall Menu
*00# Opens the mSpy User Interface
*123456789# Open the MobileSpy Menu

(The last one is only known to be available on Android but it would not harm to try the code)

For trying these codes, just open the Phone App and type in the code combination and hit the dial key. If nothing happens or you get a “not available” message, all is good – at least regarding these Spyware programs.

1.) Browser History

If somebody installed Spyware on your device, he or she might have been in a rush and forgot to delete the browser history so you can try the following:

Open Safari, tap on the book Icon then tap on the watch Icon to see the browser history. Here look for one of the following addresses:

Next, open Settings -> Safari -> Advanced -> Website Data and also look for the same addresses there.

If you can find one of these addresses, at least somebody (maybe you) visited these websites which usually will be needed when installing one of these Spyware programs.

Other Dial Codes

While talking about dial codes and even though most of you will know the following, just in case, here are some additional dial codes for other purposes:


Will show your IMEI number. (The International Mobile station Equipment Identity number is a number used to identify a device that uses terrestrial cellular networks)


This is the so called “Field Test” which provides information about cell signal, including more precise reception reading.

*67 followed by a phone number
#31# followed by a phone number

Hides your phone number to the call destination


Enable call waiting


Disable call waiting.

Call waiting is the feature that allows you to hear another incoming call when you’re already on active phone call, often referred to as a ‘beep’. Turning off Call waiting means that incoming callers will be sent directly to voicemail if you’re actively on any call with the iPhone.

Stay safe,


NetworkToolbox news

Redpark LAN cable for NetworkToolbox

NetworkToolbox uses the available interfaces (WiFi or Cell) to connect to the Internet or your local Network. Sometimes, you may want to physically connect a cable from your iPad or iPhone to a certain network device. In this case, you can use a solution I proposed in 2016 here in my post NetworkToolbox with wired Ethernet connection.

This solution uses an official Apple USB Network Adapter along with Apple’s USB to Lightning connector. The disadvantage of this solution is, that the USB to Lightning connector needs to be powered because otherwise the USB Network Adapter won’t work.

I am in close contact to Redpark for several years now. They are providing fantastic Adapters. Now, just recently they introduced a new Ethernet Cable for iPad and iPhone called L5-NET. This Adapter is better than the previously proposed solution with Apple Adapters because it’s way cheaper and because, and that’s the most important point, it doesn’t require additional powering. It can just be plugged into the Lightning socket of your device and the other end offers a plain regular network Plug.

Version 11.5 of NetworkToolbox now directly supports this cable. It now shows when the cable is plugged in and what IP Addresses are assigned to it.

Now, you can attach your device, wherever you are, to a local LAN and perform security checks directly using my App.

If you connect the cable to your iPhone or iPad, this cable is being recognized by iOS but you never know if iOS already uses the LAN Cable and it’s connection as default network device. Ideally, better switch off WiFi and Cell if you want to be certain, that the cable is used.

Now, you can also use NetworkToolbox to find out if this is the case. Just head to the Device Tool, select Network and you can see which Network interfaces are still enabled and which one is used as default interface.

NetworkToolbox news

Venmo and the Web-Service Tool of my App

Venmo (about 1.5 million users) allows people to send payments to other Venmo accounts. Venmo belongs to PayPal and is quite popular in the US especially among young people. The Venmo service lacks (for some time and still) of essential security safeguards.  Most of Venmos accounts can be freely accessed via a Web-Service by anybody. It is completely unprotected. The information available from this Web-Service includes very private and intimate data including chat messages, picture and payment information. Venmo don’t see this as an issue as their users have the possibility to opt-out for data sharing with the public but most users are not aware about that.

Now, back to my App:

NetworkToolbox contains a Web-Service Tool and this Venmo security issue is a very nice example on how to use this Tool.

We know that the so called ‘endpoint’ for the Venmo Web-Service is (where x is the number of accounts you like to receive).

To use this Web-Service, we first, open the Web-Service Tool and tap on the [=] button in the ‘Service:’ line.

On the following screen, we enter as URL for the Endpoint. Next we enter /api/v5/public?limit=20 in the URL Parameter field and hit the check-mark button to save and close this screen.

Next, back on the main page of the tool, we enter 443 for port as this is a https:// connection.

Next, we hit the Get button and will see the following results:

So we have 20 data-sets as to be expected because of the limit=20 parameter. When tapping on the data line, you will see the details of these data-sets:

And when drilling further down you will see details about the person behind this account:

Including their picture:

Don’t trust the evil.


P.S. A new update for my App will be available soon. Today I am finishing the tests, fix a few things that were reported from Beta testers (Thank you!!!) and once that’s done, I will send this update to Apple. This was indeed overdue.

P.P.S. My “Don’t trust the evil” signature was derived from Google’s “Don’t be evil”. As Google (aka Alphabet) now removed it’s slogan (probably for a reason) I wonder if I should find a new one as well ? – maybe not as this term still remains true whereas Google’s slogan was wrong all the time.

NetworkToolbox news

New Windows update 1803

Some of you may have already updated to the newest windows version 1803. In general, it is always good to update to any latest version of any Operating System or other software update because this is the only chance to stay up to date with security patches. So if you have not already updated, it’s better to do it sooner rather than later.

However, here is what I would recommend to do after installing the update:

1.) Check your privacy settings (again)

Unfortunately, with every update, MS introduces new features where privacy is turned off per default. Even worse, sometimes your privacy settings of a previous version will be disregarded and need to be enabled again.

So this 1803 update is a good opportunity to review your privacy settings again. For this, just press the Windows Key and S simultaneously and enter the term privacy in the Cortana search field of Windows.  Next, select Privacy Settings. I usually turn off almost everything.

Just go though the permissions on the left side of the screen and decide whether or not you want to enable certain permissions on the right side. Please note: often, you have to scroll on both sides (permissions and settings) and some delicate settings are only available after scrolling. I am wondering if Microsoft had a reason for that.

2.) Cortana Web Search

I use Cortana Search quite often, as described above. However, I use my favorite browser and search engine to search the web. I usually don’t like Cortana to search the web when entering a search term in the search field of Windows. Not just that Microsoft then knows what I am searching for, it’s also cumbersome to pick the right findings in the search results of Cortana if it’s mixed with web searches.

The Registry settings I was using in the past to disable this web searching behavior has changed. To disable web searching, now follow these steps:

  • Open regedit (Windows -R and enter regedit)
  • Drill down to the registry entry HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Search
  • Here, create a new 32-Bit DWORD entry called BingSearchEnabled with a value of 0
  • Next, create another 32-Bit DWORD entry called CortanaConsent also with a value of 0
  • After a restart, searches will only be performed locally

To change this back to normal, just delete these two registry entries.

Don’t trust the evil,

stay secure!


NetworkToolbox news

Getting information about an IP Address

A dear user came up with a question and I would like to share my answer with you as you might have the same question.

The question was, why is the IP Address (e.g. not working in the Whois tool and why is this IP Address converted to 3.4. ?

Short Answer: The Whois Tool requires a base domain name and not an IP Address.

But why is converted to 3.4 ?

TL;DR: When entering, the Tool assumes is a domain name with 1.2. being a subdomain of domain 3 with TLD 4. For your convenience and because Whois queries require a base domain without subdomains, it strips the subdomain part (1.2.) from what has been entered.

So far so good.

But why can’t this Tool simply automatically resolve an entered IP Address and use the resolved domain for the query. The reason is, that an IP Address could host many domains and not just one.

So what is the best way to find out more about an IP Address ?

There are basically two options in my App:

1.) The (I) Inspect Tool

First, you can try the (i) Inspect Tool. This Tool is quite powerful and provides a lot of information about any IP Address available on the network such as Domain, Reverse Domain, Provider and DNS Records – if available. From here, you can tap on the […] button and perform a Whois for each discovered Domain.

2.) The Certificates Tool

I mentioned this option a few times before, but it is still often forgotten or underestimated. What this Tool does is, it looks for any certificate available on the given IP Address. If it finds a certificate, it decodes the content and displays the result. The result reveal domain names running on that IP Address.

Below is an example for IP Address

First, the results of the (i) Inspect Tool:

Second, the results of the Certificates Tool:

So you can see, there is a lot information that can be revealed from a single IP Address using my App.

To all of you celebrating Christmas, have a Merry Christmas and all the best for 2018!

Stay safe and secure!

Best Regards,


NetworkToolbox news

A few words about KRACK

You will have heard about the KRACK (Key Reinstallation Attacks) vulnerability. I think all information (even – as usual – some over hyped and misinterpreted) is available from many sources. If you are interested, I would recommend reading Mathy Vanhoef’s information on his website

However, here is a summary:

  • The WPA2 WiFi encryption has a weakness that can be used to sniff network traffic
  • Your WPA2 password can not be discovered by this attack, however it is not necessary for sniffing the traffic by using this attack
  • Almost all routers and WiFi Network devices are affected (including iPhones and iPads using the current iOS Versions)
  • This vulnerability can (only) be fixed with updates on both ends, Router AND Client

What to do:

  • Look for updates (for your Router AND your Clients). Throw away devices that can’t be updated.
  • Until updates are installed, prevent using sensitive information (e.g. Banking) on any WiFi device. Better use cabled devices for this.
  • If you really have to, double check if you are indeed using HTTPS while submitting sensitive information. Man-in-the-middle attacks, which are possible by using this vulnerability, will most of the time cause HTTPS connections to end up as HTTP connections in order to capture the traffic.
  • Carefully look out for unusual logins on your accounts or anything else unusual. In doubt, change passwords for accounts using cabled devices.
  • After everything calms down, take this opportunity to change all your passwords

Don’t trust the evil,




NetworkToolbox news

☛ NetworkToolbox, iOS 11 and MAC Addresses

Last time, when iOS 10.2 has been introduced, the ability for NetworkToolbox to show MAC Addresses was no longer available as Apple has removed access to MAC Addresses due to security concerns and to increase our privacy. (see MAC Addresses are back)

It was a real challenge to find a workaround to be able to show the MAC Address again. My solution still works under iOS 10.3.3.

Now, with iOS 11 knocking at the door, you may wonder if it will still work. The answer is no. Unfortunately. Apple made my workaround unusable again in iOS 11.

I already investigated into this again for several days (and nights) but it seems, this time, Apple did a great job. They even fixed some additional (severe) security issues I found last time while I was looking for an alternative to get the MAC Address.

However, the consequence of this on iOS 11 is now, not only the lack of the ability to show the MAC address. The main disadvantage is, that I no longer can display the device Vendor, which is derived from the MAC Address using the internal MAC Database. This is and was a very valuable information while scanning a local network as it often helps to identify a device. Unfortunately, this is gone now.

I spoke to two Apple employees. Both told me, that Apple wants to protect users against Developers who misuse the MAC Address to track user activities and they said that this has precedence over the missing feature for my App.

I told them that this is a very good approach with good intentions but even without a MAC Address there are a couple of (even easier) ways to track user activities and, depending on the setup, a MAC Address can even be derived from IPv6 Address and that there isn’t much Apple can do against it.

I also recommended to add a security setting which could be used to allow/disable MAC Address access similar to camera or microphone access. So users can decide which App should be allowed to have access to the MAC Address.

One of these Apple employees told me that he is using my App quite often and found my statements and suggestions quite reasonable.

I am not sure (I even doubt) that my conversation with Apple will change the situation but maybe if more people (like you) would let Apple know, maybe it will.

Nevertheless, here are the plans for my next steps:

  • Shortly after iOS 11 has been released, I will create another Update of NetworkToolbox

(Shortly ‘after’ because I want to create an update based on and for the final iOS 11 version which makes sense as the App already runs just fine on iOS 11 (except for the MAC Address) and thus, wouldn’t require an immediate update)

  • I will give the MAC Address issue another (short!) try but will not waste too much time. Instead, I will polish the Network Scanning tool that it will provide as much usability as possible even without a MAC Address
  • Finally and in addition, that next update will include things, I already worked on (most of them have already been finished).


Thanks for your suggestions, which helped to make this App even better.

Stay tuned,



NetworkToolbox news

To Petya or NotPetya

You will have heard about the recent attack to Windows PCs called Petya or NotPetya.

The reason why some people say NotPetya is, that it is not a new version of the former Petya malware, even though it looks so.

This one is again (like WannaCry) based on the recently released NSA Tools (see my related post here).

But it is worse than WannaCry and was just built to create chaos and damage on as many systems as possible. The current damage is already massive. I bet you will hear more about it during the next days.

I will not repeat all the rumors about the source or intentions here.

Here is just, what I have done and what you should do (sorry, I should rather say “have to do”):

  • BACKUP BACKUP BACKUP (everything you don’t want to loose, your Pictures, Movies, Documents, Source-code, Letters, Tax Statements, Banking Documents etc.)
  • UPDATE UPDATE UPDATE (everything PCs, Routers, NASes, Mobile Devices)
  • Replace or switch off your Windows XP PCs
  • Do this on every Windows PC:
    • Start a command prompt with admin rights (right click on the Windows Icon in the lower left corner and select ‘Command Prompt (Admin)’
    • And type:

These commands will create three files perf, perfc.dll and perfc.dat and will mark them read only. The current version of NotPetya will stop working if these files were found. This is a very simple thing and most likely, a new version of NotPetya will disregard these files. However it doesn’t hurt and has no other side effect.

Finally, if you are already infected, for instance if you see a sudden Checkdisk message trying to repair your hard-drive or anything else unusual:

  • Immediately switch off your PC (even if Checkdisk says you should not)
  • Disconnect your PC from your network
  • Try to boot it stand alone. If this doesn’t work anymore, most likely, your data is lost.
  • Switch off your router / disconnect from the Internet
  • Check your other PCs as you might have a chance that they are not yet infected.

Don’t trust the evil.



NetworkToolbox news

NSA Tools available to everybody – Update your PCs. Quick!

As you may have heard, a Group called Shadowbrokers have stolen Hacking tools from the NSA and made them available to the public.

I had a chance to take a look at these tools. A few days ago they already released some tools but those tools were quite outdated and not really harmful if you don’t use an old Windows XP or Vista PC. But these new tools are indeed up-to-date and I was able to use the tools to compromise one of my Windows 10 PCs which hasn’t been updated for a few days. After it was updated with the latest Creators Update from Microsoft including all security updates, that was no longer possible.

The NSA Tools also include tools to disable or hide themselves against all known virus scanners, including Microsoft.

There are rumors that NSA has informed Microsoft about the fact that their tools were stolen along with information about the vulnerabilities these tools are using so Microsoft was able to fix these vulnerabilities. This makes sense as these vulnerabilities are existing for quite some time now and it is interesting that Microsoft has created these fixes before Shadowbrokers have released the Tools to the public.

About the NSA tools

Some people already asked if these hacking tools are indeed from the NSA or ‘just’ from Hackers. I have seen many similar tools by many developers and of course developed my own. The available tools have been developed in Java, Python and Perl, some are available as binaries.

Even though I found some humor like in the Zippybeer tool which contains an ASCII image like this:

I found the code really really well organized and straight forward. Typical hacker code contain typos, they often don’t really care about code quality and a lot of code I have seen looks really ‘messy’ or even contains messages to other hackers. This code looks excellent, very reliable and foolproof with a lot of try/catch and exception handling to ensure that the tools are doing what they are supposed to do or fail and let the user know why and not leaving a trace. This code hasn’t been developed in a rush and it is indeed professional, just like a commercial software. This is why I am pretty sure that it comes from the NSA.

What you need to do

So if you didn’t already, hurry and update your Windows PCs. If you are using older Windows Versions than Windows 10, disconnect them from the internet.

This is not because of the NSA as they may have already (or soon) finished new tools which will still be able to compromise your PC. This is mainly because these NSA tools are now available to the public. They are easy to use and I suspect not only by people with good intentions.

Don’t trust the evil.

Happy Easter.


NetworkToolbox news

Major CloudFlare data leak on millions of Websites – and Apps

CloudFlareNormally, you may find your stolen Email addresses and sometimes even stolen passwords in wrong hands because a certain website has been individually compromised – like happened with Adobe, DropBox or Yahoo recently.

Even though the Yahoo breach with more than 500 million affected user accounts sound like a major breach, a recent CloudFlare data leak has a new dimension.

CloudFlare is a service, used by millions of websites, to improve availability and speed. CloudFlare servers are working between the visitor of a website and the website itself and can be seen as a kind of cache.

What happened was, that since September 22nd 2016 and February the 18th 2017, CloudFlare had a bug which resulted in CloudFlare to respond back to the website visitor with memory contents of the CloudFlare servers instead of the contents of the visited website.

These memory contents often contain sensitive data of other websites such as API Keys, security tokens or even internal server and database passwords. Not only that this data may contain your personal data, even worse, with this information, the effected website and database can be compromised.

Things got worse as this leaked content has already been indexed by Search Engines like Google over the past Months. The issue with this is, that the data is now (still) available to everybody and can easily be found by using special Search terms. Google and other Search Engines are working on deleting such contents but it will be almost impossible to get rid of all leaked data.

Nick Sweeting provides a zipped list of sites (so far, he found more than 4 million sites) that are using CloudFlare which might be affected by this leak.

Not only Websites but also Apps (iOS and Android) such as FitBit and Uber are affected as they also use CloudFlare for data exchange. Data of such Apps have also been found by searching Google.

So what can you do?

Not much to be honest but you can take this as a gentle reminder to:

  • Change passwords frequently
  • Don’t use one and the same password for different services
  • Use fake accounts and fake Email addresses for registration wherever possible
  • Don’t trust the evil

Best regards,


NetworkToolbox news

Online shopping risks – check your store before placing an order!

Happy New Year everyone!

Yesterday, the German BSI warned (again!) about thousands of online stores worldwide which have been infected by online criminals in order to capture user’s payment data. Many store owner have been informed by the BSI some time ago but less than a half of them have fixed that issue.

Shopping on those still infected or unpatched stores is a high risk! Most likely, your payment data will end up somewhere else.

In 2015, Willem de Groot revealed this issue in the popular shopping software Magento which is widely used around the world.

Which scares me most is the fact that by that time, there were 3501 Stores infected, in March 2016 Willem found 4476 infected stores and late 2016 there were almost 6000 infected stores worldwide. Here is a list:

Fortunately, MageReport provides a tool, to check if a certain website is already infected or at least unpatched and a possible victim for cyber criminals.

So I would recommend to use that tool to check the online shops you are using before using them again.

I did so and guess what, three of them were infected – only one of them replied back to me after I informed them about their issue.


Don’t trust the evil!


NetworkToolbox news

MAC Addresses are back – Happy and secure Holidays

Today, Apple released my Update 9.02.03 which will bring back the MAC Addresses and fixes the Crash in the Device Tool reported by some users.

MAC Addresses

Bringing back the MAC Addresses was really a challenge and caused me some more gray hair and long nights during the last days. With iOS 10.2 Apple continued with their good intentions to protect our privacy by removing all sorts of information that might be misused by developers to uniquely identifying our devices. Apples approach is a good approach and I appreciate that in general. However, this has caused that I was no longer able to show the MAC Addresses in Network Scans anymore which was quite unfortunate as the MAC Addresses were also used along with the included MAC Database to show the vendor of each device. Finding a solution was really a challenge as I have to use official APIs because otherwise Apple would have rejected the App. The solution I found is indeed using official Apple APIs but in a very specific and unusual way (don’t want to elaborate more). This said, I expect Apple to even close this door at some point.

Device Tool crash

This was also a challenge. Some user reported the Device Tool to crash (one user even left a one-star bad review only because of this crash). I tried to reproduce this on any of my various test devices without success. Fortunately, some users contacted me regarding this crash (Thanks again!) and I asked those users to enable crash-log submission in iOS (Settings -> Privacy -> Diagnostics & Usage -> Automatically Send, then enable “Share With App Developers”). When switched on, Crash logs will be submitted to Apple and a few days (sometimes a week) later I am able to download anonymized logs from Apple. These logs showed that indeed for a few users, the App crashed for security reasons as it wasn’t allowed to access motion sensor data (Motion data will be accessed in the Device Tool for the Sensor section). The question is still, why only a few users were affected and why I was (and I am still not) able to reproduce this on all of my test devices. However, I hope at least I fixed this in the new version 9.2.3. If not, please let me know.


Thank you so much for all your reviews. It was overwhelming to read them all. Unfortunately they are now gone with this update but I don’t want to bother you again asking to update your review.

Instead, please have relaxing and secure Holidays.

Thank you all and let’s work together for a more secure 2017!

See you in 2017.

Best regards – and don’t trust the evil.


NetworkToolbox news

iOS 10.2 and missing MAC Addresses

Dear Users,

it seems that Apple has further improved their security measures in iOS 10.2. Unfortunately, this results in wrong MAC Addresses in NetworkToolbox.

I am currently working on a workaround so please be patient and wait for this fix.

Best Regards,


NetworkToolbox news

ALERT: Major attack to Routers. 41 Million Routers worldwide on risk.

alarmMajor attacks to routers are currently ongoing. These attacks already resulted in major outages of the German Telekom network and others in many countries.

The attack is using an old vulnerability on port 7547. This port is basically the interface for the Telecom companies to configure a router remotely. A variant of Mirai currently uses this vulnerability to install a bot using this interface.

Here is, what you can do:

1.) Restart your router

This will clean your router in case it was already affected. However, even after a restart, it may happen that the router will get infected shortly after by another attack as this attack is currently still going on.

2.) Check if your router is vulnerable

For this, you need to perform a reverse (from outside) Portscan on your public IP Address and Port 7547 by following these steps from NetworkToolbox:

– Select the Devices Tool
– Tap on Network
– Locate the Public IP Address
Take down this public IP Address (or bookmark to the Logbook)
Switch off (disable) WiFi mode on your device

Next, ensure that NetworkToolbox can use the Celular/Mobile network as follows:

– Quit NetworkToolbox
– Open Settings
– Tap on Celular Data
– Search for “NET-Toolbox” on the list
– Ensure that the switch for NET-Toolbox is switched ON


– Reopen NetworkToolbox
– Tap on the Portscan Tool
– As Address, enter the Public IP address you took down previously
– As Port enter 7547
– Tap on Scan

You should get an empty list (0 Results). If that’s not the case, your router might be vulnerable.

3.) Protect your router

First of all, you should look for a firmware update. German Telekom currently provides an update for the effected router which is installed automatically after restarting the router. Other may need to look for a router update on the suppliers/vendors website.

After an update has been installed, I would recommend to perform another portscan.

In addition, I suggest to disable this port if possible. Some Routers, like the German Telekom Routers, offer an option to disable the remote configuration feature which will also disable port 7547. On the German Speedport routers this feature is called “Easy Support”. On other routers it might be called “TR-069” or similar.

I would suggest to switch this feature completely off. Please note: if you are using a rented router, your provider may not be happy about this as they can no longer look into your router in case of issues.

Once the port can not be accessed from outside, you should be safe.

Some more background information:

As mentioned before, port 7547 will be used for remote access configurations on your router using a so called TR-069 interface. This interface is quite safe as it uses a callback feature that ensures that only the valid provider can access and change the configuration data.

This interface will also be used for instance by a Synology NAS if you would allow the NAS to configure your router on your behalf for convenience.

However, due to a bug in older implementations of the TR-069 protocol, this interface can also be used for code-injection.

So an open port 7547 alone does not mean you are vulnerable but along with a buggy firmware you are.

Then, either updating the firmware or disabling TR-069 (or closing the port if the router offers such a possibility) would fix a possible issue. If possible, I would suggest to do both (updating and closing the port).



NetworkToolbox news

Mirai and Yahoo


You may have heard about the biggest DDOS attack ever against my colleague Brian Krebs. Brian’s Website has been attacked by devices on the internet which have been compromised by a malware called Mirai (please visit Brian’s website for more details).

I read the source code of Mirai and developed a new security check for you which will be available in NetworkToolbox after checking  for the latest data update in the settings. This new security check will scan for the same vulnerabilities Mirai is using to infect devices.

So you may want to run this security check on some or all of your network devices. If the security check reports a certain device is vulnerable, it doesn’t mean it is already ‘infected’ by Mirai but if Mirai would by chance pass by and visit your network, it is most likely that it will infect that device.

According to what I have seen while inspecting the code, fortunately Mirai will disappear once you restart the infected device. So what you should do, once the new security check reports a vulnerable device is, to restart that device and either remove it from your network or try to update it’s firmware and perform another Security check.


You may also have heard of the latest news about Yahoo.There are three strong arguments why to leave Yahoo as soon as possible:

  1. As mentioned in previous posts, Yahoo is about to be sold. Most likely to Verizon. You may also remember my post of Verizon’s Super-cookie.
  2. 500 Million Yahoo accounts have been hacked.
  3. Yahoo has scanned all mails for NSA and FBI.

A single fact from the above list should be enough to say good bye to Yahoo but I am still surprised to receive many Questions and Support mails from user with Yahoo accounts.

A few weeks ago, I was about to block all Yahoo mails as this would reduce the amount of Spam mails quite a lot (Spam is probably a fourth reason against Yahoo). But since I still receive so many Yahoo mails, I decided against blocking yahoo.

Your question might be, what else should I use? Google? Definitely not! Keep in mind (and this applies very much to Yahoo as well): “Nothing is for free”. Think twice: why should a company who needs to earn money to pay at least their employees offer a service such as Email for free? If you want security, you have to pay – period.

My best advise is, to look for one of the many service Providers who offer simple web-hosting and Email services for a good price and (most important) with a good reputation. Such a provider can be used to register your favorite domain name such as your surname (or combinations like for instance) and they can run a well working Email service for you. This way, you will have personalized and nice Email addresses combined with a reliable and secure Email server. Such (good) providers will also take care of Spam and While/Black listing. Often way better than the big guns like Yahoo or Google.

For a temporary time, you can forward your Yahoo (or Google) mails to this address.

Don’t be trust the evil.