This deletes some old code that apparently has been broken and somewhat unused for many years.
The 'derived_implementor?' method for modules relies on the debug output from Ruby in order to tell of a class implements a method, but the regex it used didn't work properly with any modern Ruby version until 2.5.x. This caused a random sleep to get inserted into certain payload staging operations, which actively breaks staging in certain scenarios (I'm not trying to address that here).
This also removes some ancient module feature detection code, which also is entirely unused today.
To round out the work done by mihi for x86 stages back in the day,
this PR provides x64 Windows stage encryption in RC4 via assembly
written/modified by max3raza during adjacent work on DNS tunneled
transport.
Stage encryption differs from encoding in that there is no decoder
stub or key materiel carried with the stage which can be used by
defensive systems to decode and identify the contents. Persistence
payloads, oob-delivered stage0, and other contexts benefit heavily
from this as their subsequent stage is difficult to detect/identify,
and the chance of accidental execution of the wrong payload/stage
is drastically reduced if separate keys are in play for individual
targets - acquiring the wrong stage will result in decryption
failure and prevent further execution.
For historical context, all of the RC4 stagers implement in-place
decryption via stage0 for the contents of stage1 using the provided
passphrase converted to a key and embedded in stage0 as part of the
payload.
Testing:
In-house testing with Max - we got sessions, loaded extensions.
Notes:
All credit for the work goes to Max3raza - big ups for getting
this knocked out.
Matthew Kienow
Brent Cook
Tim W
h00die
Aaron Soto
bwatters
Wei Chen
Erin Bleiweiss
Green-m
UserExistsError
Pierre Lestringant
scriptjunkie
Jeffrey Martin
Summus6
RageLtMan