When source code to a relatively obscure, Unix-based Internet relay chat
(IRC) client was reported to be "backdoored" last month, security
professionals collectively yawned.
But last week, when three popular network security programs were reported
to be similarly compromised, security experts sat up and took notice.
Now, it appears that the two hacking incidents may have been related.
According to program developer Dug Song, the source code to the Dsniff,
Fragroute, and Fragrouter security tools was contaminated
on May 17th after an attacker gained unauthorized access to his site,
In an interview today, Song said affected users are being contacted, but he
declined to provide details of the site compromise, citing an ongoing
When installed on a Unix-based machine, the modified programs open a
backdoor accessible to a remote server hosted by RCN Corporation, according
to an excerpt of the contaminated Fragroute program posted Friday to Bugtraq
by Anders Nordby of the Norwegian Unix User Group.
In another posting to the Bugtraq mailing list last Friday, Song reported
that nearly 2,000 copies of the booby-trapped security programs were
downloaded by unsuspecting Internet users before the malicious code was
discovered May 24th. Only 800 of the downloads were from Unix-based
machines, according to Song.
Song's subsequent Bugtraq message said that intruders planted the
contaminated code at Monkey.org after successfully penetrating a machine
operated by one of the site's administrators. The attackers exploited
"client-side hole that produced a shell to one of the local admin's
accounts," wrote Song in his message.
The exploit code planted at Monkey.org was nearly identical to a backdoor
program that was recently slipped by attackers into the source code of the
Irssi IRC chat client for Unix.
According to a notice posted May 25th at Irssi.org, someone "cracked" the
distribution site for the IRC program in mid-March and altered a
configuration script to include the back door.
NEW PRECAUTIONS IMPLEMENTED. Installing the compromised Irssi program provided a remote server hosted by
FastQ Communications with full shell access to the target machine, said the
notice. Irssi's developer, Timo Sirainen, was not immediately available for
Today, the Web server at the Internet protocol address listed in the
backdoored Irssi code returned the message: "All your base are belong to
Meanwhile, Unknown.nu, the collocated server listed in the backdoored
Monkey.org code, today displayed the
home of the Niuean Pop Cultural Archive.
When contacted by SecurityFocus Online, the site's administrator, Kim
Scarborough, said he was unaware that the machine had been used by the
Monkey.org remote exploit.
Scarborough reported that he completely reinstalled the server's system
software, including the FreeBSD operating system, on May 30th after
discovering evidence that someone had hacked into it.
According to Scarborough, he had installed the Irssi chat client on the
machine around May 17th at the request of a user.
The two security incidents have forced authors of the affected programs to
implement new measures to insure the authenticity of their downloadable
According to a page at
Irssi describing the backdoor, new releases will be signed with the GPG
encryption tool, and the author will periodically review the programs for
Song said that Monkey.org has implemented technology to restrict user
sessions, and that he is considering adding digital signatures to software
distributed at the site. By Brian McWilliams