The malware seeded by pirated software months ago and creating what was dubbed iBotnet by Symantec security researchers proves the concept of botnets on Apple systems, but doesn't achieve major botnet status.
An article in the April issue of Virus
by two Symantec
researchers says malware
for the Apple Macintosh from January was used to create a botnet,
the botnet attempted a denial-of-service attack.
The malware attacks at the time were noteworthy: They hid
inside what apparently pirated copies of Apple's iWork software and Adobe
The programs were spread through BitTorrent and other
Symantec identified the malicious code as OSX.Iservice.
According to Mario Ballano Barcena and Alfredo Pesoli of Symantec Ireland,
OSX.Iservice created a backdoor on the systems that allowed control to be
issued from a small number of specific hosts. A remote attacker could use a
vocabulary of 31 commands: socks, system, httpget, httpgeted, rand, sleep,
banadd, banclear, p2plock, p2punlock, nodes, leafs, unknowns, p2pport, p2pmode,
p2ppeer, p2ppeerport, p2peertype, set, get, clear, abortall, p2pihistsize,
p2pihist, platform, script, sendlogs, uptime, uid, shell, and rshell.
Barcena and Pesoli identify this as the first attempt to create a botnet of
Macs, and say that in January the botnet attempted to perform a DoS attack on a
Website. They find the Photoshop version of the bot especially interesting in
that it abuses some of the Mac OS' own authorization interfaces.
The "iBotnet," as it has been dubbed, spread to only a few
thousand Macs before it was identified, and is said to be easy to identify and
remove if you are looking for it. The question, as I see it, is why you would look
to identify it if you had been infected to begin with. The sort of person who
installs a pirated program and runs an installer as root, which is required for
this attack, isn't likely to be running an anti-malware program. Few enough
innocent users on Macs run anti-malware software.
Kevin Haley, director of Symantec Security Response, noted that the pirated
applications aren't actual working copies of the programs, and it's possible
that some would notice that. It's not so clear that they would remove the
application or that removing it would remove the bot. This is even clearer with
the Photoshop version, according to Haley. It is quite possible that the user might
never know the malware had been downloaded. However, the user might notice some
problems on his or her machine. But even if thousands of Mac bots of this type
are still out there, they're likely harmless at this point as they won't be
connecting to a C&C.
What's important about this episode is that it does prove the concept of a
Mac botnet. Like Linux and Vista, the Mac runs with users
unprivileged by default and attempts either to fail or raise the prominence of
potentially infectious activities such as installing privileged services.
But give a credulous or unsophisticated user a reason to install a
privileged service, such as to install what they think is iWork, and they'll do
it. There's your bot; nothing on the Mac makes it all that hard to do, and the
really weak link is on the other side of the keyboard.
Editor Larry Seltzer
has worked in and written about the computer industry since 1983.
For insights on security coverage around the Web, take a look at eWEEK.com
Security Center Editor Larry Seltzer's blog Cheap Hack.