Threat Level: green Handler on Duty: Yee Ching Tok

SANS ISC: InfoSec Handlers Diary Blog - SANS Internet Storm Center InfoSec Handlers Diary Blog

Sign Up for Free!   Forgot Password?
Log In or Sign Up for Free!

PCAPs and Beacons

Published: 2021-03-07
Last Updated: 2021-03-07 20:55:50 UTC
by Didier Stevens (Version: 1)
0 comment(s)

I like taking a closer look at captures files posted by Brad. In his latest diary entry, we have a capture file with Cobalt Strike traffic.

With regular expression "^/....$" I look for URIs that are typical for Cobalt Strike shellcode (and Metasploit too):

Following this HTTP stream, I see data that looks encoded and has some repetitions, so this might be some kind of XOR encoding:

I export this data stream as a file:

Then pass it through my Cobalt Strike beacon analysis tool:

And this is indeed the configuration of a beacon.

Didier Stevens
Senior handler
Microsoft MVP

Keywords: beacon pcap
0 comment(s)
Diary Archives