Parent class: VirWare
Viruses and worms are malicious programs that self-replicate on computers or via computer networks without the user being aware; each subsequent copy of such malicious programs is also able to self-replicate. Malicious programs which spread via networks or infect remote machines when commanded to do so by the “owner” (e.g. Backdoors) or programs that create multiple copies that are unable to self-replicate are not part of the Viruses and Worms subclass. The main characteristic used to determine whether or not a program is classified as a separate behaviour within the Viruses and Worms subclass is how the program propagates (i.e. how the malicious program spreads copies of itself via local or network resources.) Most known worms are spread as files sent as email attachments, via a link to a web or FTP resource, via a link sent in an ICQ or IRC message, via P2P file sharing networks etc. Some worms spread as network packets; these directly penetrate the computer memory, and the worm code is then activated. Worms use the following techniques to penetrate remote computers and launch copies of themselves: social engineering (for example, an email message suggesting the user opens an attached file), exploiting network configuration errors (such as copying to a fully accessible disk), and exploiting loopholes in operating system and application security. Viruses can be divided in accordance with the method used to infect a computer:- file viruses
- boot sector viruses
- macro viruses
- script viruses
Class: Email-Worm
Email-Worms spread via email. The worm sends a copy of itself as an attachment to an email message or a link to its file on a network resource (e.g. a URL to an infected file on a compromised website or a hacker-owned website). In the first case, the worm code activates when the infected attachment is opened (launched). In the second case, the code is activated when the link to the infected file is opened. In both case, the result is the same: the worm code is activated. Email-Worms use a range of methods to send infected emails. The most common are: using a direct connection to a SMTP server using the email directory built into the worm’s code using MS Outlook services using Windows MAPI functions. Email-Worms use a number of different sources to find email addresses to which infected emails will be sent: the address book in MS Outlook a WAB address database .txt files stored on the hard drive: the worm can identify which strings in text files are email addresses emails in the inbox (some Email-Worms even “reply” to emails found in the inbox) Many Email-Worms use more than one of the sources listed above. There are also other sources of email addresses, such as address books associated with web-based email services.Read more
Platform: Win32
Win32 is an API on Windows NT-based operating systems (Windows XP, Windows 7, etc.) that supports execution of 32-bit applications. One of the most widespread programming platforms in the world.Description
Technical Details
Cosol is a worm virus spreading via the Internet as an email attachment. This worm also has a backdoor and key-spy routines.
The worm itself is a Windows PE EXE file about 355Kb in size (compressed by UPX, its decompressed size is about 675Kb), written in Delphi.
The infected messages have an attached EXE file with a name randomly selected from the following variants:
cosol.exe mirch.exe myprog.exe Anti.exe projekt2.exe eb.exe Vis.exe msn.exe Buch.exe Tach.exe
The message body is also randomly selected from several variants:
Heloo!!!
I send you this program
I think you like it
Hi!,
This is my Cool program
run this program, you mast like
Have do you do!!!
I sent this program, special for you.
Take the atachment and run!!!
Cosa activates from infected emails only when a user clicks on the attached file. The worm then installs itself into the system and runs the spreading, backdoor and key-spy routines. During installation the worm creates the following files in the Windows directory:
DC220.EXE - worm copy BIOS.EXE - one more worm copy CSOLP.EXE - worm component
Cosa registers the following files in the system registry auto-run key:
HKLMSoftwareMicrosoftWindowsCurrentVersionRunServices
rundll = %WindowsDir%DC220.exe
HKLMSoftwareMicrosoftWindowsCurrentVersionRunOnce
rundll32 = %WindowsDir%csolp.exe
The worm also creates and runs a decoy program:
Program FilesCommon FilesRASKR.EXE
A subdirectory (subdirs) is created in the Windows directory and is where Cosol writes its temporary files:
syssend sysmai sysem
Backdoor
The backdoor routine enables remote operation of an infected computer. It also reports disk and file information, creates, deletes and executes files, sends master files from the infected computer to the "master" comptuer, looks for password files (including WebMoney files) and sends them as well to the "master" computer with remote operation access. Files affected by the backdoor routine:
*.kwm
*.mag
*.pwl
*.pwm
*R��??*.txt
*pass*.txt
*? �R'�*.txt
*R� �??*.exl
*R��??*.exl
*pass*.exl
*? �R'�*.exl
The key-spy routine logs all keys pressed on the keyboard and sends this information to the "master" computer with remote access.
Read more
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