POP3: .CRT

This signature detects e-mail attachments that have the extension .crt and were received through POP3. Because .CRTs (Security Certificate) files can contain executable code, this can indicate an incoming e-mail virus. Attackers can create malicious executable code, tricking users into executing the file and infecting the system.

Extended Description

Since .crt files contain executable code, malware writers can exploit this by inserting malicious code. A target system is compromised if an unsuspecting user opens a malicious .crt file, which is usually received by e-mail. The impact on the target system is dependent on the instructions contained in the malicious .crt file.

References

URL: http://www.cknow.com/vtutor/FileExtensions.html http://www.novatone.net/mag/mailsec.htm http://support.microsoft.com/?kbid=235309

Short Name

POP3:EXT:DOT-CRT

Severity

Major

Recommended

False

Recommended Action

Drop

POP3: .CRT

Extended Description

References

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