Uncategorized
1

Hidden VNC for Beginners

Hidden VNC is a creative solution to a solution to a problem which stemmed from banking fraud. Back years ago when fraud was uncommon, most banks only had basic IP or Geo-location checks to flag or block accounts if someone logged in from another computer. To combat this, banking trojans …

Uncategorized
4

Windows 10 System Call Stub Changes

Recently I installed Windows 10 RTM and while I was digging around I happened to notice some changes to the user mode portion of the system call stub: these changes appear to break the current methods of user mode system call hooking on x86 and WOW64 (Recap: here). Windows 10 x86 …

Uncategorized
2

Intercepting all System Calls by Hooking KiFastSystemCall

Usually I don’t post things like this, but because KiFastSystemCall hooking only works on x86 systems and doesn’t work on Windows 8 or above, it no longer has much use in malware. There are also multiple public implementations for this method, just not very elegant, which I hope to correct. …

Uncategorized
4

Bootkit Disk Forensics – Part 3

Getting Original Pointers XP is a little more complicated than newer systems due to the use of a single driver for both port and miniport; however, getting the original pointers is fairly straight forward depending on how you do it. IRP_MJ_SCSI & DriverStartIo – Method 1 (Windows XP) A common …

Uncategorized
10

Bootkit Disk Forensics – Part 2

DriverStartIo As I explained in the previous article: DriverStartIo is used by older miniports to actually perform the disk I/O, it takes 2 parameters (a device object and an IRP), exactly the same as IoCallDriver does. The call to DriverStartIo is done with IoStartPacket; however, the device object passed is …

Uncategorized
9

Bootkit Disk Forensics – Part 1

Recently I got the idea to play around with bypassing bootkit disk filters from an email i received, which highlighted that my MBR spoofing code was able to get underneath the driver of a popular forensics tool, preventing it from reading the real disk sectors. Although I believe disk forensics …

Uncategorized
6

Using Kernel Rootkits to Conceal Infected MBR

If you’ve look at any of the major bootkits such as TDL4 and Rovnix, you’ve probably noticed they employ certain self defense features to prevent removal; specifically, intercepting read/write requests to the boot sectors. While these defense mechanisms can fool some software, they may, in some cases, make infections even …

Uncategorized
3

Virtual File Systems for Beginners

A virtual File System (VFS), sometimes referred to as a Hidden File System, is a storage technique most commonly used by kernel mode malware, usually to store components outside of the existing filesystem. By using a virtual filesystem, malware developers can both bypass antivirus scanners as well as complicating work …

Uncategorized
6

Coding Malware for Fun and Not for Profit (Because that would be illegal)

A while ago some of you may remember me saying that I was so bored of there being no decent malware to reverse, that I might as well write some. Well, I decided to give it a go and I’ve spent some of my free time developing a Windows XP …

Uncategorized
2

The 0x33 Segment Selector (Heavens Gate)

Since I posted the article about malware using the 0x33 segment selector to execute 64-bit code in an 32-bit (WOW64) Process, a few people have asked me how the segment selector actually works deep down (a lot of people think it’s software based). For those who haven’t read the previous …