Virus Database

04h.635

Description 04h.635

This is a harmless memory resident parasitic virus. It hooks INT 21h. On DOS calls FindFirst (AH=4Eh), it searches for COM files and writes itself to the beginning of the file. The virus contains the encrypted text strings:
04h Virus*.com

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I-Worm.Cuerpo

Description I-Worm.Cuerpo

This Internet worm infects computer with installed Windows 9x and Internet Explorer 5.0 without Scriptlet.TypeLib hotfix (MS99-032). The worm spreads via E-mail by sending infected messages from affected computers. While spreading the worm uses MS Outlook and sends itself to all addresses that are stored in MS Outlook Address Book. The worm also has alternate spreading method that does not use Outlook at all.
The worm arrives to a computer as email message in HTML format. The subject of message may be vary. Message body has no visible text but contain script that is worm itself.
At the moment message is opening or displayed in preview pane, script activates and worm's code executing. At this moment ActiveX warning may appear on display:
An ActiveX control on this page might be unsafe to interact with other parts
of the page. Do you want to allow this interaction?
[YES] [NO]
Choosing [NO] will not allow the worm to execute.
Being activated worm drops some files that are worm's parts, gets access to Outlook and spreads using it, then searching on computer hard drive for email addresses, collects them and use in alternate spreading routine.
Composing infected message to send, the worm choosing subject from one of existing messages from Outlook Inbox. The worm also attaches HTML file with worm code. File name is name of one of attachments existing in inbox with added "(9 Kbytes).vbs". Thus, infected message contain worm code twice - in the message HTML body and in the attachment.
The worm adds itself to all signature files used by MS Outlook. This means every composed message in HTML format will contain worm code.
The worm replaces Internet Explorer start page with blank one. Four days after infection the worm replaces start page again with URL pointed to "http://www.freedonation.com".
The worm has alternate spreading method that does not use Outlook at all. This routine searches on local hard drive for files with extensions "txt", "na2", "wab", "mbx", "dbx" and "dat" (these are usual extensions for mail databases) and then searches and collects e-mail addresses in these files. Collected addresses then posted (using HTML form) to worm's author internet site. Special script on that site send infected messages directly from site to every address received. Such messages have same address in "From" and "To" fields and contain only HTML body with worm code inside. This alternate spreading method will not work as soon as worm author's site will be closed.

I-Worm.Cult

Description I-Worm.Cult

This is a worm virus spreading via the Internet being attached to infected emails and through the Kazaa file sharing network. The worm also has a backdoor component.
The worm itself is a Windows PE EXE file about 13Kb of length (compressed by FSG).
Installing
While installing the worm copies itself to the Windows system directory with the "winupdate.exe" name and registers that file in the system registry auto-run keys:
HKCUSOFTWAREMicrosoftWindowsCurrentVersionRunOnce
Microsoft auto update = winupdate.exe

HKLMSOFTWAREMicrosoftWindowsCurrentVersionRun
Microsoft auto update = winupdate.exe

The worm also creates a system registry key and keeps its internal data in there:
HKLMSOFTWAREMicrosoftWDXDriver
stv1=
stv2=
stv3=
stv4=
xdvd=

The worm then displays fake error message:
Application Error

The instruction at |0x776456de| referenced memory at |0x623525dg3|. The memory
could not be |read|
Click on OK to terminate the application

Spreading: EMail
The infected messages have following fields:
Subject:
Hi, I sent you an eCard from BlueMountain.com

Message body:
To view your eCard, open the attachment
<
If you have any comments or questions, please visit
http://www.bluemountain.com/customer/index.pd

Thanks for using BlueMountain.com.

Attached file name:

BlueMountaineCard.pif

The worm activates from infected emails only in case a user clicks on the attached file. The worm then installs itself to the system and runs spreading routines.
Spreading: Kazaa
The worm creates subdirectory with the "Kazaa" name in Windows system directory and copies itself to there with the names:
"SMS_sender.exe"
"DivX 5.03 Codecs.exe"
"Download accelarator.exe"
"PaintShop Pro 7 Crack_By_Force.exe"
"ZoneAlarm Pro KeyGen.exe"

The "Kazaa" directory is then registered as Kazaa file sharing resource.
The Backdoor Routine
The backdoor routine connects to an IRC channel, listens to commands from its "master" and performs several actions by "master"'s request:
- reports system information
- downloads a file from an URL
- runs files
- e.t.c.

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