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Bekijk Volledige Versie : a dangerous fast spreading (yet simple) trojan horse.



Gadi Evron
27/10/03, 19:45
I usually do not email about "new" trojan horses unless they have
something "special" about them, for there are a lot of them coming out
non-stop. However, with this one,
Although quite simple, is very destructive and spreading at incredible
speed.

The trojan horse spreads by people going to different URL's to download
a *.jpg (started with britney.jpg).

The jpeg is actually an HTML file, and when the web browser receives it,
it thinks that it is a server error message for the file not existing,
and loads the page.

In the page we find a javascript line, that using hex encoding in an
attempt to hide what it does, downloads patch.exe and replaces
mplayer.exe with the new file.
patch.exe connects to the mIRC DDE server, causing mIRC to spam, and
then it start ruining the system's registry. Starting to delete keys at
root and enumerating from there, one at a time.
What I signify, and forgive my language, as an "Hump and dump" trojan
horse.

This reminds me of the first patch.exe trojan horse, that was purely a
destructive file - back in 95/96.

I would also like to commend angelfire for shutting down the first web
page this appeared on very quickly. They always respond to abuse in a
timely manner. The geocities page is still up last time I checked.

Not very complicated, but interesting, and very dangerous.

Gadi Evron (i.e. ge),
ge@linuxbox.org.

--------
gevron@netvision.net.il
PGP Key: 2048/2048 (Size) 0x2D3D6741 (ID).
Fingerprint: 0EB3 00BC 974B 3C2B 336D 6486 ECA5 2D0D 2D3D 6741.

Andreas Reich
27/10/03, 23:00
Gadi Evron wrote:
> The jpeg is actually an HTML file, and when the web browser receives it,
> it thinks that it is a server error message for the file not existing,
> and loads the page.

Not necessarily. Often it is just a directory named xyz.jpg. The browser
then
gets redirected to /url/xyz.jpg/ and loads the index.html there.

-Andreas

Craig Holmes
28/10/03, 01:45
I also noticed this on irc. I grabbed a copy of the file before it was taken
off line if anyone has any interest in seeing it:
http://gearbox.gearbolt.net/files/security/cap/britney.jpg
Note that I have commented out the function call that start the exploitation
to keep anyone from using my box to spread this virus.

Craig Holmes
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