I assume what's really going is this.
The terrorist is given a USB drive with the TrueCrypt software
and an encrypted partition/file. The first thing the terrorist does is
put the USB drive into a computer, run the TrueCrypt program, then mount
the file/partition, entering a password. In other words, all you see on
the USB drive is the directory "TrueCrypt", and a large file that is
the encrypted "container", as you see in the picture of the "F:" drive.
Once the terrorist mounts the container, she then opens that new folder. It'll contain a copy of a PGP program, like gpg4win.
The terrorist runs that GUI. You see that on the right with the "G:"
drive, with a 'portable' version of GPG installed in the encrypted
container.
The terrorist types in the message, then encrypts it. The terrorist
chooses one of the many public keys that have been stored inside this
encrypted container (G:) within the USB flash drive (F:).
Then the terrorist runs a 'portable' web-browser from the G: drive.
These are browsers based on Chrome or Firefox that run completely
self-contained from a directory, leaving behind no other trace on the
system. In this example, I'm using "Iron Portable", which is based on
Chrome. All the settings, like which website to log into, and possibly
saved passwords, are stored in this directory. Likewise, any logs will
be stored here.
The terrorist then logs onto a forum, such as a typical phpbb one using SSL.
The terrorist then create a new message, and copies/pastes the
encrypted text from the clipboard. In this example, I'm showing the
"Gentoo" forums, which is well-known to be visited by various
ne'er-do-wells and sympathizers.
This system works because it's completely contained on the USB drive. The terrorist can walk up to any Windows PC at a cyber-cafe and make this work. All the evidence is on the USB drive, so there's nothing left on the Windows computer that law-enforcement can track down. Likewise, the forum is likely to be something that the NSA is less likely to be monitoring. But if they are, they'll get some metadata, but still won't be able to break the PGP encoding.
This is all guesswork. I built this USB drive in the last hour and installed all the portable versions of the software (TrueCrypt, gpg4win, and IronPortable) on it to create these screenshots. It's a plausibly useful way of doing things such that stupid terrorists can't mess things up (leave unencrypted messages or metadata around). And, it matches (kinda) the garbled news account.
The moral of the story is that news stories ought to talk to experts. We can't figure out from the inaccurate accounts you can tell, and only make guesses like I have here.
http://blog.erratasec.com/2016/03/some-other-comments-on-isis-dead-drop.html#.V8R6oKL_rnk
This system works because it's completely contained on the USB drive. The terrorist can walk up to any Windows PC at a cyber-cafe and make this work. All the evidence is on the USB drive, so there's nothing left on the Windows computer that law-enforcement can track down. Likewise, the forum is likely to be something that the NSA is less likely to be monitoring. But if they are, they'll get some metadata, but still won't be able to break the PGP encoding.
This is all guesswork. I built this USB drive in the last hour and installed all the portable versions of the software (TrueCrypt, gpg4win, and IronPortable) on it to create these screenshots. It's a plausibly useful way of doing things such that stupid terrorists can't mess things up (leave unencrypted messages or metadata around). And, it matches (kinda) the garbled news account.
The moral of the story is that news stories ought to talk to experts. We can't figure out from the inaccurate accounts you can tell, and only make guesses like I have here.
http://blog.erratasec.com/2016/03/some-other-comments-on-isis-dead-drop.html#.V8R6oKL_rnk
