How to decode Java code safely?

  • Thread starter Thread starter Gabriele Neukam
  • Start date Start date
G

Gabriele Neukam

Hi all,


I received one of these infamous "you received a greeting card" mails,
and this time, the body is empty.

Below the HTML sectino (y<es, *below*) is a snippet of Java code, which
is probably designed to exploit the Java loopholes which have already
been mentioned here.

What I'd like to know, is how to deciver the gibberish - it is
deliberately encrypted, to hide what it is about to do. Is there any
tool or site, that will decrypt and display the content? The URL where
the malign code is to be downloaded from, must be hidden in the
encrypted text...


Gabriele Neukam

(e-mail address removed)
 
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Gabriele said:
Hi all,


I received one of these infamous "you received a greeting card" mails,
and this time, the body is empty.

Below the HTML sectino (y<es, *below*) is a snippet of Java code, which
is probably designed to exploit the Java loopholes which have already
been mentioned here.

What I'd like to know, is how to deciver the gibberish - it is
deliberately encrypted, to hide what it is about to do. Is there any
tool or site, that will decrypt and display the content? The URL where
the malign code is to be downloaded from, must be hidden in the
encrypted text...
Click to expand...

I don't suppose it pretended to come from (e-mail address removed)? If so I've had
one recently. I opened it in Outlook Express set up in "Internet Zone",
rather than the default "Restricted Zone" using Virtual PC. Don't do this
on your computer, whoever may read this :-)

It downloaded a rootkit keylogger which NOD32 detected and chewed up. (Once
NOD32 was turned off) It did a rather crap job of rootkitting though
because "type" worked on one of the files, and the filing-system stealthing
hid so many files from view it was obvious something was amiss, before
running RootkitRevealer. As usual it hooked into winlogon and set itself to
run in safe mode.

Virus Total
_______________________________________________

Scan results
File: file.exe
Date: 02/10/2006 11:14:19 (CET)
- ----
AntiVir 6.33.0.81/20060210 found nothing
Avast 4.6.695.0/20060209 found nothing
AVG 718/20060210 found nothing
Avira 6.33.0.81/20060210 found nothing
BitDefender 7.2/20060210 found [BehavesLike:Trojan.WinlogonHook]
CAT-QuickHeal 8.00/20060210 found [(Suspicious) - DNAScan]
ClamAV devel-20060126/20060209 found nothing
DrWeb 4.33/20060210 found nothing
eTrust-InoculateIT 23.71.72/20060209 found [Win32/Haxdoor.Variant!Trojan]
eTrust-Vet 12.4.2074/20060210 found [Win32/Haxdoor!generic]
Ewido 3.5/20060210 found [Backdoor.Haxdoor.gh]
Fortinet 2.54.0.0/20060210 found [suspicious]
F-Prot 3.16c/20060209 found nothing
Ikarus 0.2.59.0/20060209 found [Backdoor.Win32.Haxdoor.GH]
Kaspersky 4.0.2.24/20060210 found [Backdoor.Win32.Haxdoor.gh]
McAfee 4693/20060209 found nothing
NOD32v2 1.1402/20060209 found [a variant of Win32/Haxdoor]
Norman 5.70.10/20060209 found [W32/Haxdoor.SA]
Panda 9.0.0.4/20060209 found nothing
Sophos 4.02.0/20060210 found [Troj/Haxdor-Gen]
Symantec 8.0/20060210 found nothing
TheHacker 5.9.4.094/20060210 found nothing
UNA 1.83/20060209 found [Backdoor.Haxdoor]
VBA32 3.10.5/20060209 found [suspected of Trojan-Downloader.Agent.84]
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Adam said:
It downloaded a rootkit keylogger which NOD32 detected and chewed up.
Click to expand...

I forgot to mention that once the rootkit was installed, NOD32 still
detected it and removed it completely. </plug> :-)

Adam Piggott, Proprietor, Proactive Services (Computing).
http://www.proactiveservices.co.uk/

Please replace dot invalid with dot uk to email me.
Apply personally for PGP public key.
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Gabriele Neukam said:
I received one of these infamous "you received a greeting card" mails,
and this time, the body is empty.

Below the HTML sectino (y<es, *below*) is a snippet of Java code, which
is probably designed to exploit the Java loopholes which have already
been mentioned here.
Click to expand...

If it's like some I've received from post[at]postcard.com, the script
(Javascript, not Java) is between the body tags within the html.
What I'd like to know, is how to deciver the gibberish - it is
deliberately encrypted, to hide what it is about to do. Is there any
tool or site, that will decrypt and display the content?
Click to expand...

It decodes itself with a custom made function. You can tweak the
script by creating a html file for it, removing the quoted-printable
by replacing "=3D" with "=", and replacing the "document.write" with
an instruction to display the generated code in a textarea. You also
need to tidy up some other stuff.

Let me know if you want the details.
The URL where the malign code is to be downloaded from, must be
hidden in the encrypted text...
Click to expand...

It creates an invisible iframe which links to several exploits.
Spamless has given a thorough description in nanae of what happens:

http://groups.google.com/group/news.admin.net-abuse.email/msg/fd8e19c1b2193a7d
 
On that special day, Ant, ([email protected]) said...
Below the HTML sectino (y<es, *below*) is a snippet of Java code, which
is probably designed to exploit the Java loopholes which have already
been mentioned here.
Click to expand...

If it's like some I've received from post[at]postcard.com, the script
(Javascript, not Java) is between the body tags within the html.
Click to expand...

There are possibly *several* versions which have been sent to many
people.

Someone in Germany managed to decode the stuff, and reported:

<quote>
Ist einfach ein Frameset, das auf 64.71.167.15 / support / leitet.

Diese Seite wirft einen nochmal so ein Ding zum Fraß vor. Exakt
gleicher
Encoder (wie langweilig).

Das geht dann weiter nach www.asikral.com / clientscript /.

Da endet die Spur, denn <TITLE>509 Bandwidth Limit Exceeded</TITLE>.
</quote>

Translated: It is a frameset that redirects to 64.71.167.15/support,
which contains more of the gibberish, which again leads to
www.asikral.com / clientscript, where the further content cannot be
fetched, as the bandwidth is already exceeded. Go figure.


Gabriele Neukam

(e-mail address removed)
 
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Gabriele said:
Someone in Germany managed to decode the stuff, and reported:

<quote>
Ist einfach ein Frameset, das auf 64.71.167.15 / support / leitet.

Diese Seite wirft einen nochmal so ein Ding zum Fraß vor. Exakt
gleicher
Encoder (wie langweilig).

Das geht dann weiter nach www.asikral.com / clientscript /.

Da endet die Spur, denn <TITLE>509 Bandwidth Limit Exceeded</TITLE>.
</quote>

Translated: It is a frameset that redirects to 64.71.167.15/support,
which contains more of the gibberish, which again leads to
www.asikral.com / clientscript, where the further content cannot be
fetched, as the bandwidth is already exceeded. Go figure.
Click to expand...

That's exactly where my copy of the email went for the malicious code (the
IP address and host name), which was not over its bandwidth at the time.

I also found it didn't work each time - I had to open the email four or
five times to get it to download enough for me to grab the malicious programs.

I have been reading the German threads, using the Google Language tools to
translate it :-) The breakdown that was given there was what I experienced
to the letter, so I think it was the same email.

Cheers,


Adam.
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Gabriele said:
Hi all,


I received one of these infamous "you received a greeting card" mails,
and this time, the body is empty.

Below the HTML sectino (y<es, *below*) is a snippet of Java code, which
is probably designed to exploit the Java loopholes which have already
been mentioned here.
Click to expand...

Had another one today, going to a different site. This one just killed OE
after opening up a JavaScript prompt with a long string of characters for
the title. Couldn't see that it managed to accomplish anything after
killing OE, it might do something different on Win9x/XP, I've only got
access to a Windows 2000 testbed.

Add smsapi.info to your blocking lists!
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Gabriele Neukam said:
On that special day, Ant, ([email protected]) said...


This looks quite complicated. These many click commands mentioned in
the posting, are they trying to make use of this exploit?

http://www.securiteam.com/windowsntfocus/5MP0B0UHPA.html
Click to expand...

That link talks about about a drag-and-drop exploit relying on the
timing of a pop-up window, whereas Spamless is describing an html help
vulnerability (among several others) which also depends on persuading
the browser to run content in a more trusted security zone.

So, I don't think drag-and-drop is involved, but you never know, he
may have missed something.
 
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