Covid-19 led to a globe-wide work-from-home experiment, and it is logical to expect the growing number of users accessing their computers remotely using Remote Desktop. Having an RDP port open to the Internet is generally considered insecure, and most of the security experts advise using VPN or/and two-factor authentication to improve the security. Here we will review an… Read More »
One of our customers has recently reported that WinpkFilter installation has failed with error code 0x800700b7. This was the first report mentioning such error code, and we have spent some time to research the issue at a customer side. Such behavior seems to be worth mentioning in a dedicated post. 0x800700b7 error code can be decoded as ERROR_ALREADY_EXISTS.… Read More »
Why do I need to bridge or a couple of real life cases when you may need an alternative to built-in Windows network bridge? Over ten years have passed since I have published the first version of Ethernet Bridge. The main purpose of this simple tool, inspired by Steve Gibson from Gibson Research Corporation, was supporting OpenVPN in… Read More »
Recently, I have had a small but curious research project with the requirement to decrypt ProtectedHomepages binary value stored under [HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\CurrentVersion\AppContainer\Storage\microsoft.microsoftedge_8wekyb3d8bbwe\MicrosoftEdge\Protected – It is a violation of Windows Policy to modify. See aka.ms/browserpolicy]. While googling around the problem, I have seen a related question on Stack Overflow, so I decided that it may have sense to share… Read More »
There is a very popular and important question about Windows Packet Filter: “Can I handle Gigabit traffic in WinpkFilter user-mode application without noticeable performance degradation?”. I was asked rather frequently and usually, my answer starts with “that depends…” followed up by various performance related considerations and ends with a sentence “if you need maximum possible performance then consider… Read More »
Venturing into Windows driver development can be an intimidating endeavor, especially if it’s your first time. You may find yourself asking, “Where do I start?” Comprehensive tutorials abound on creating drivers for the latest versions of Windows, but guidance on doing so for legacy systems can be more challenging to locate. This guide aims to provide clear, step-by-step… Read More »
This is a short reverse engineering review of one useful remote administration utility, originally authored by Mark Russinovich (you can download it from Microsoft web-site here). The original version of this review was published on this site in 2004, but since the utility is still very popular and users are interested about its internal design, I decided to… Read More »
The original version of this article was published on this site over 14 years ago and was named “Firewall for Windows” (firewalls were popular at that time, however the same kind of drivers can be used for the wide variety of networking applications). Lots of time has passed so far, and described old Windows operating systems are mostly… Read More »