Pierluigi Paganini July 06, 2017

WikiLeaks leaked documents detailing BothanSpy and Gyrfalcon CIA implants designed to steal SSH credentials from Windows and Linux OSs.

WikiLeaks has published a new batch of documents from the Vault7 dump detailing two new CIA implants alleged used by the agency to intercept and exfiltrate SSH (Secure Shell) credentials from both Windows and Linux operating systems with different attack vectors.

The first implant codenamed BothanSpy was developed to target Microsoft Windows Xshell client, the second one named Gyrfalcon was designed to target the OpenSSH client on various Linux distros, including CentOS, Debian, RHEL (Red Hat), openSUSE and Ubuntu.

BothanSpy and Gyrfalcon are able to steal user credentials for all active SSH sessions and then sends them back to CIA cyber spies.

BothanSpy is installed as a Shellterm 3.x extension on the target machine, it could be exploited by attackers only when Xshell is running on it with active sessions.

Xshell is a terminal emulator that supports SSH, SFTP, TELNET, RLOGIN and SERIAL for delivering industry leading features including a tabbed environment, dynamic port forwarding, custom key mapping, user defined buttons, VB scripting, and UNICODE terminal for displaying 2 byte characters and international language support.

“BothanSpy only works if Xshell is running on the target, and it has active sessions. Otherwise, Xshell is not storing credential information in the location BothanSpy will search.” reads the user manual.

“In order to use BothanSpy against targets running a x64 version of Windows, the loader being used must support Wow64 injection. Xshell only comes as a x86 binary, and thus BothanSpy is only compiled as x86. Shellterm 3.0+ supports Wow64 injection, and Shellterm is highly recommended.“

The implant could collect full or partial OpenSSH session traffic, it stores stolen information in a local encrypted file for later exfiltration.

“Gyrfalcon is an SSH session “sharing” tool that operates on outbound OpenSSH sessions from the target host on which it is run. It can log SSH sessions (including login credentials), as well as execute
commands on behalf of the legitimate user on the remote host.” reads the user manual of Gyrfalcon v1.0.

“The tool runs in an automated fashion. It is configured in advance, executed on the remote host and left running. Some time later, the operator returns and commands gyrfalcon to flush all of its collection to disk. The operator retrieves the collection file, decrypts it, and analyzes the collected data”

Wikileaks also published the user guide for Gyrfalcon v2.0, the implant in composed of  two compiled binaries that should be uploaded by attackers to the target platform.

“The target platform must be running the Linux operating system with either 32- or 64-bit kernel
and libraries. Gyrfalcon consists of two compiled binaries that should be uploaded to the target
platform along with the encrypted configuration file. ” continues the malware.

“Gyrfalcon does not provide any communication services between the local operator computer and target platform. The operator must use a third-party application to upload these three files to the target platform.”

Below the list of release published by Wikileaks since March: