Thread by @mtoecker

I had a chance to look at the IOT compromise mentioned in @dangoodin001 's article here: arstechnica.com/information-te…

It opens an encrypted reverse shell to the IP mentioned, and forwards a shell to them. Pretty clever, not novel.

There is however an interesting wrinkle, there is a bug in the script. See if you can find it, or continue on for ...

The script is supposed to attempt to connect, and if unsuccessful 30/60 times it will kill itself and delete the evidence.

The file /tmp/.c is used as a loop counter to do this by echoing a new value every time a connection is attempted.

But at the circled point, the author accidentally put the new loop counter into /tmp.c instead, which means the loop counter never increments, and never reaches 30.

This works fine if it connects to their C&C server, cause when they kill the connection the script will still erase the evidence.

But, if someone has been good about their outgoing traffic policy for IOT devices, then this script will attempt to connect every 10s FOREVER.

#OOOPS

So, any network admin looking at denied connections over a 24 hour period is going to see ~14,400 connection attempts from their printers. Each.

I think I'm going to repurpose this script for pentests, minus the error. It's actually pretty slick.

You can redirect it to your own IP if you want, and set up a listener with

>> sudo ncat -lvnkp 443 --ssl

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