W32.Blebla.Worm | 
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This worm arrives with one of several different subject lines and has two attachments named Myjuliet.chm and Myromeo.exe. Once you read the message, the two attachments are automatically saved and launched. When launched, this worm attempts to send itself out to all names in the Microsoft Outlook address book using one of several Internet mail servers located in Poland. Otherwise this worm does no harm to the infected system.
Damage
Distribution
The W32.Blebla.Worm was first reported in Poland. The worm arrives as an email message that has an HTML body and two attachments named Myjuliet.chm and Myromeo.exe. The subject of the email is selected randomly from the following set:
- Romeo&Juliet
- :))))))
- hello world
- !!??!?!?
- subject
- ble bla, bee
- I Love You ;)
- sorry...
- Hey you !
- Matrix has you...
- my picture
- from shake-beer
This worm functions only under Windows 95, Windows 98, and Windows 2000 systems that have not been updated with the latest vulnerability updates from Microsoft. It does not run under Windows NT. The HTML component saves the attachments in the \Windows\Temp folder, and then executes the Myjuliet.chm (compiled HTML) file. That file then launches the Myromeo.exe file, which is the mass-mailer component of the worm. When executed, the Myromeo.exe file looks for the running copy of HH.exe (that is associated with .chm files) and tries to stop it in order to hide its activity. In the meantime, a task with Romeo&Juliet as its name can be seen in the task list.
Next, the virus queries the Microsoft Outlook address book, and tries to propagate itself using six different mail servers that are located in Poland. Several of these servers are not currently available, and others are protected from nonauthenticated email traffic. However the worm might be able to spread inside Poland by the users of these particular mail servers:
- 213.25.111.2 memo.gate.pl
- 194.153.216.60 mail.getin.pl
- 195.117.152.91 dns.inter-grafix.com.pl
- 212.244.199.2 gate.paranormix.net.pl
- 195.116.62.86 madmax.quadsoft.com
- 195.117.99.98 promail.pl
The virus has its own email engine. It attempts to connect to one of the these servers and tries to send its email message with MIME-encoded attachments. The size of the mailer component is 29,184 bytes. It is written in Borland Delphi, but the code is packed using the popular UPX packer. The original unpacked code would be about 60 KB.
Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":
- Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
- If a blended threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
- Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
- Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
- Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
- Isolate infected computers quickly to prevent further compromising your organization. Perform a forensic analysis and restore the computers using trusted media.
- Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
To recover from this infection:
- Run LiveUpdate to make sure that you have the most recent virus definitions.
- Start Norton AntiVirus (NAV), and run a full system scan, making sure that NAV is set to scan all files.
- If any files are detected as infected by W32.Blebla.Worm, delete them.
Write-up by: Peter Szor
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