sesh

sesh = silent exploitation shell | security engineering shell | super epic shell | stealth espionage shell | standalone execution shell | sexy encrypted shell

a linux shell for pentetration _^testing

features

• fully modular - enable/disable any feature at compile or runtime

• total disregard for active leveraging of established conventions

• does not touch disk without you knowing about it

• read and write files without changing metadata

• assume the identity of an already running process (or whatever you want it to be)

• in-memory command history

• embed arbitrary files in the binary for later use

• configuration can be saved as a short string, which can be loaded with ease

• built in enumeration scripts

• spoof running time (may need root)

• something like a cooler version of moonwalk

• ignore SIGHUP (and/or other signals)

• cool udp and tcp revshell capability, which when combined with the previous feature, means you can ssh (or whatever) to a target, run sesh, close ssh connection, and then reconnect via a more stealthy route (alla pwncat)

• send random data to random (or not so random) ip addresses to cover communications

• many useful tools built in, don't need to run binaries from disk, such as:

  • cat, base64, zip, tar, netcat, nano, ls, find, grep, wget, su, env, chmod, chown, chgrp, getcap, setcap, etc
  • (note that most of these will be replaced with cool rewrites, i.e. ls->exa, find->bfs, etc. will be kinda like busybox but more based.)
  • might also just chuck python in there

• run executables from memory, from network, or even local binaries with or without +x set

  • not sure if I can do this, but optimally, given a binary in any of the above forms, you would be able to execute them with userland exec without overwriting the original sesh process, i.e imagine you are in a sesh session, and you run silentexec /bin/ls, this would read the ls binary, execute it with userland exec, show you the output, then return you to your sesh session, all without starting or stopping any processes at all!
  • ok I thought a bit more about the above idea, and I think I can basically (before sesh performs a userland exec) patch the target binary (in memory) in such a way that rather than exiting post-execution, it instead would itself perform a userland exec to get back to sesh. This would mean losing whatever state sesh was previously in though, which might be a problem, but I could probably save the state and restore it using a method similar to that used by CryoPID.
  • alternatively perhaps I should basically somehow spin up a userland virtual machine sort of thing. I'll have to investigate that avenue.
  • less cool version: through the use of memfd, like this

• ability to start a process as a child of some arbitrary process (cursed+hard), or maybe something like this to start the process inside another process without causing any issues with the original process

• awesome backdooring using a project I haven't started writing yet, which involves infecting preexisting executables with a self-replicating security flaw (thanks Johnny!)

Warning

Written in Go!!!