Here's a computer virus story that's not an urban legend.
If you receive an attachment in e-mail called "picture.exe,"
don't open it. If you do, what happens next reads a bit like a spy novel -- this Trojan
horse drops two more programs called note.exe and manager.exe which will search through
your internet cache directory and, if you have one, the directory that holds your America
Online username and password. It then encrypts that information, tries to establish an
Internet connection, and sends it all to an e-mail address in China.
Picture.exe first surfaced right before Christmas, when some Net users
were spammed with e-mail with the subject line "batty." Several postings to
Usenet virus groups followed; then Network Associates engineers received several e-mail
alerts to what appeared to be technically not a virus but a Trojan horse. (A Trojan horse
does not replicate on its own, but a virus does.)
Network Associates has since updated its McAfee virus program to detect
picture.exe (If you already have the software, an updated version can be downloaded from this site),
but many questions remain about the prying program.
"This is a more interesting Trojan than normal," said Vincent
Gullotto, manager of the antivirus emergency response team for Network Associates.
"It actually has the capability to take information and send it someplace. This one
goes further than most and if it's successful can use the information against you."
A prying program:
Network Associates received an unusually large number of e-mails from victims of
picture.exe, and there are already dozens of Usenet posts with security experts warning
about the danger.
Here's how it works:
Once a recipient opens picture.exe, that file expands into two other executables --
note.exe and manager.exe -- and places them into the Windows subdirectory. The following
line is also added to the win.ini file: "run=note.exe." That makes note.exe run
the next time Windows is started.
According to Network Associates, note.exe then gathers information,
apparently looking through the temporary Internet cache directory in an attempt to
determine what Web sites users have visited. It then encrypts that information into a DAT
file. It also appears to look in the directory where AOL user information is stored.
Note.exe then builds a second DAT file.
"It's unclear right now what the second DAT file is for,"
Gulotto said.
Usenet poster David Crick, a British computer science student who
received the e-mail Dec. 23 and started the Usenet discussions, said, "I thought when
I started downloading a very large e-mail: 'Either someone's sent me an interesting piece
of software, or it's a virus.' It turned out to be a combination of the two -- an
interesting virus," he said.
Crick says the file employs a crude encryption technique, a 5-digit
ASCII character shift -- where a=f, b=g, and so on. Other Usenet posters say the DAT file
is full of e-mail addresses.
After note.exe does its thing, manager.exe runs, attempting to e-mail
the encrypted file to a e-mail addresses with the domain of a Chinese ISP. The recipient,
of course, could be anywhere.
"It appears to try to gain access to an ISP," Gulloto said.
Several Usenet posts say that upon reboot, the Trojan horse opens up dial-up networking
and tries to dial out of the infected PC.
There are many unanswered questions -- chief among them, why China?
Gulotto said last year his firm worked on a similar Trojan horse/virus with the same M/O.
Called SemiSoft, it also gathers information and tries to send it to an e-mail address
hosted in China. Network Associates is continuing to study picture.exe.
America Online was not available for comment.
