W32.Qint@mm

SUMMARY

This is a Internet worm that arrives as a email disguised as a message from Microsoft Technical Support.

Protection

• Virus Definitions (Intelligent Updater) August 30, 2001

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Easy

Damage

• Damage Level: Medium
• Payload: Encrypting executable applications with a random encryption key
• Modifies Files: EXE files

Distribution

• Distribution Level: Low
• Subject of Email: Invalid SSL Certificate
• Name of Attachment: sslpatch.exe
• Size of Attachment: about 12K

TECHNICAL DETAILS

This worm tries to spread by using SMTP. It uses a single SMTP server. Thus it is fairly simple to stop the propagation of the worm by taking care of that server and using proper SMTP mail setttings. The server is not available at the moment. It seems that its administators are working to solve the problem already. However it is very unlikely that this worm could ever cause any problems because of its implementation flaws.

This worm attempts to encrypt EXE files by using the Microsoft Crypto API with random a encryption key. The idea was previously seen in W32.Crypto virus in a slightly more advanced form 2 years ago. The worm will check if there is an Internet connection. If there is a connection, it searches for all files that have the extension .ht* in the My Documents folder. It then extracts email addresses from those files and emails itself to the email addresses that it found. The actual attachment is MIME encoded.

The message is as follows:

From: "Microsoft Support" <support@microsoft.com>
Subject: Invalid SSL Certificate
Attachment: Sslpatch.exe
Message:

Hello,
Microsoft Corporation announced that an invalid SSL certificate that web sites use is required to be installed on the user computer to use the https protocol. During the installation, the certificate causes a buffer overrun in Microsoft Internet Explorer and by that allows attackers to get access to your computer. The SSL protocol is used by many companies that require credit card or personal information so, there is a high possibility that you have this certificate installed. To avoid of being attacked by hackers, please download and install the attached patch. It is strongly recommended to install it because almost all users have this certificate installed without their knowledge.

Have a nice day,
Microsoft Corporation
   

Recommendations

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.

REMOVAL

1. Run LiveUpdate to make sure that you have the most recent virus definitions.
2. Start Norton AntiVirus (NAV), and run a full system scan. Be sure that NAV is configured to scan all files.
3. Delete all files that are detected as W32.Qint@mm.

NOTE: If the worm has executed, any files that it encrypted are not recoverable. If you find that programs no longer run, you will have to reinstall the software.