A blog about malware and file formats

Malcat version 0.9.0 is out! You can now open multiple files in parallel, scan for FLIRT signatures, analyse onenote files and enjoy quick bookmarks handling, in addition to the usual bug fixing and various QOL improvements

New version 0.8.5 is out! Enjoy the new "big file" mode, an improved disassembly view, advanced Yara integration and VHD + FAT filesystem support, as well as many other improvements.

Windows shortcut files can contain valuable data. We will see how to extract the most information out of a .lnk downloader and will manually extract the configuration file of the final cobalt strike beacon using malcat

New version 0.8.4 is out! Enjoy support for ubuntu 22.04 / python 3.10! We've also improved the analysis of LNK and NSIS files, added more than 400000 API hashes in our constant database and malcat can now identify and parse Cobalt strike configuration files.

New version 0.8.2 is out! Enjoy blazing fast stack strings detection for x86/x64, CD/DVD file system browsing, Py2Exe scripts disassembly and lzma streams detection.

We will statically unpack and emulate a malicious NSIS installer running multiple shellcodes, up to the final Lokibot password stealer and its configuration.

New version 0.8.0 is out! New RTTI analysis, VTGrep integration, improved python + Golang disassembly, color themes and advanced selection.

When one faces obfuscated code, it is sometimes more efficient to focus on the data instead. By using Malcat's different views and analyses (and a bit of guessing as well), we will show how to statically unpack an excel downloader and the following obfuscated native dropper without (much) reverse engineering.

New version 0.7.88 is out! Added MSI installer decompiler, improved scripting documentation and added Joe Sandbox threat intelligence lookup.

We will unroll a maldoc spam exploiting CVE-2018-0798 leading to a multi-staged Delphi dropper abusing steganography and cloud services to conceal its payload

Our target is a 2-layers .NET dropper using multiple cipher passes (XOR, AES ECB and AES CBC + PBKDF2) to finally drop a Loki sample. Without even starting a debugger, we will show how to unpack it 100% statically using Malcat's builtin transformations and the python scripting engine.