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Add AES256 secret policy blob decryption support (SCCM)

Open 1058274 opened this issue 4 months ago • 0 comments

The block cipher algorithm for task sequence blobs in SCCM secret policies seems to have changed from 3DES to AES starting from (I believe) SCCM version 2403. You can recognize 3DES and AES blobs with the prefixes 8913 and 8A13 respectively. Surprisingly, none of the existing public SCCM tools seem to support this yet which can result in missing out on high-value credentials.

This PR adds support for the decryption of such AES-encrypted blobs when using ntlmrelayx with the --sccm-policies flag to dump secret policies from the SCCM MP using a relay. Testing has been done with Ludus SCCM Lab that by default runs on a version before 2403 and which you can manually upgrade to the latest available version on the SCCM site server. This allows easily reproducing the situation before and after.

1058274 avatar Aug 11 '25 20:08 1058274