Before yesterdayPentest/Red Team
27 May 2022 at 09:33
One day, I was trying to bypass an EDR and I noticed something interesting. The EDR I was trying to bypass wasn’t hooking the DLL in their code with jmp instruction like other EDRs in user-land. In this case, it was hooking directly the Import Address Table. This technique makes the usual move like live-patching, or erasing the loaded DLL with one freshly loaded from disk useless. I had to unhook the Import Address Table of my process.
24 March 2022 at 11:12
The analysis on this post was made from a Windows 10 x64 bits. If you are trying to compare the content of this post on a lower Windows version you will be disappointed since changes were made in Windows 10. In my last post dedicated to the different ways to retrieve Syscall ID, I explained quickly how direct syscalls were performed in User Mode and remained vague about how it was processed in Kernel Mode.
- Alice Climent-Pommeret
- EDR Bypass : Retrieving Syscall ID with Hell's Gate, Halo's Gate, FreshyCalls and Syswhispers2
29 January 2022 at 19:13
This post is not an extensive presentation of Hell’s Gate1, Halo’s Gate, FreshyCalls2 or Syswhispers23. You can find detailed explaination on these techniques on their Github repo, various articles and the amazing Sektor7 Windows Evasion Course4. So whats the point of this article then ? Well, I find the various techniques used to dynamically retrieve syscall identifiers very interesting and I wanted to present the difference between them. Soooo let’s begin shall we ?
6 December 2021 at 17:07
Damn my Import Address Table is hooked! One day at work, I was trying to bypass an EDR and I noticed something interesting. The EDR I was trying to bypass wasn’t hooking the DLL in their code with jmp instruction like other EDRs in user-land. In this case, it was hooking directly the Import Address Table. This technique makes the usual move like live-patching, or erasing the loaded DLL with one freshly loaded from disk useless.
5 December 2021 at 18:50
A long time ago, in a galaxy far far away, I was having fun reversing NotPetya. Files dropped by NotPetya During the dynamical analysis, I identified some files dropped on the disk by the sample. Files dropped in the disk An executed file using named pipe One of them caught my eye: it is executed by the sample with a named pipe argument. A binary executed with named pipe argument
5 December 2021 at 14:45
We are going to learn how to steal the passphrase of a drive encrypted with default setup on a Debian distribution. How? Through physical intrusion! The general idea is simple. By default, disk encryption on Debian (and many other distributions) doesn’t encrypt the \boot directory. Even if full disk encyprtion is available via Grub2… To perform this attack, we are going to use a Live USB on the target machine. Using the live USB, we are going to modify the script asking the passphrase (located in /boot) to make it write, in a text file, the passphrase typed by the victim.
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