Copies of OpenSSH packages on popular download sites have been trojaned, developers have warned.

Overnight it was realised that the tarball for OpenSSH 3.4p1 on the
main openBSD (ftp.openbsd.org) mirror was compromised, after developers noticed that the checksum of the package had changed. Other mirror sites might also be affected.

The malicious code is not particularly sophisticated but it is a remotely controllable program that could give potential attackers root access to victim's machines. The backdoor is in the makefile that comes with the package, not the OpenSSH software itself.

Initial analysis suggests that code has been added to the package which generates a shell script which, when compiled, tries to contact 203.62.158.32 (web.snsonline.net) on port 6667. It seems that the trojan is executed during build only.

Who compromised the openSSH package and their motives remain unclear.

OpenBSD developers have been informed on the issue, and a clean-up operation can be expected to commence shortly. For now, however, users would do well to exercise extreme caution in updating their machines.

OpenSSH is a free version of the SSH (Secure Shell) communications suite and is used as a secure replacement for protocols such as Telnet, Rlogin, Rsh, and Ftp. ®

External Links

Copy of Weblog by Australian developer Edwin Groothuis analysing the problem
Other developers sound the alarm bells