Didier Stevens

A small update for my translate.py program.

Python function Xor takes now 2 extra, optional arguments:

hexadecimal: a boolean, by default False.

When True, the key is provided as an hexadecimal string.

rotation: an integer, by default 0

This is the number of bytes to rotate the key to the left. For example, when the key is ABCD, a rotation value of 1 yiels key BCDA.

translate_v2_5_12.zip (http)
MD5: 4B0C79AF8A1D41BA735C5030912E6C28
SHA256: 899109A9D787D6781AEB0569330A01709063BB3FD58F4AED068A57951B230F88

This update to jpegdump.py, my tool to analyze JPEG images, brings 2 small changes:

Data between segments can be selected with suffix d. Like this: -s 10d

This means: select the data between segments 9 and 10.

And when option -E is used to add hash values, repeating hashes are marked with parentheses.

jpegdump_V0_0_10.zip (http)
MD5: 5B33C0ECB94E3284CA64E98B5A0947C3
SHA256: D8C657DB7564160725C95677BE200EB3A902BDC74CF335EFA8499596495633F0

This is a bug fix version and also adds updated statistics.

1768_v0_0_16.zip (http)
MD5: E72E66BE5A66DC2C6E1806DE82DF9B39
SHA256: 008E15C617EE94D849A3325643497D216E559609602E97CF2EE41968CCA5D096

Some new features that help with analyzing memory dumps.

Here is the analysis of a VMware vmem file:

There’s a new sanity check, determining if an extracted configuration is OK or not OK (NOK).

A config passes the sanity check if it contains a valid payload type and a valid public key.

Configurations that don’t pass the sanity check, are most likely false positives: they have a valid header, but no valid fields. They can show up in memory dumps of Windows machines.

Option -S can be used to hide configurations that don’t pass the sanity check:

Now we are just left with detections of the sleep mask routine. What’s new in this version, is that the position where the signature was found is listed.

Finding both 32-bit and 64-bit routines is unusual.

Option -V can be used to dump 256 bytes before and after the signature, to help us get an idea what we are dealing with.

And what we actually found here, is the memory of the anti-virus program containing signatures, like signatures for Cobalt Strike sleep mask deobfuscation routines.

1768_v0_0_15.zip (http)
MD5: 15EBA21D59D78ED9A674DC2B88687555
SHA256: 73987F1B8577A5C31B2D7BDC197A465F8700B3F3C7838A31802BD77FFC872C42