‘Olympic’ emails contain malicious XLS attachments

Malware writers sprint to use vulnerabilities before next Patch Tuesday.

Security researchers have reported seeing emails containing XLS attachments designed to exploit a yet unpatched vulnerability in several versions of

Microsoft

‘s

Excel

software.

The attachment, which purports to contain information about this summer’s Olympic Games in Beijing, leaves a trojan on the user’s computer. After opening a backdoor, the trojan also drops a non-malicious

Excel

file, tricking the user into believing that the attachment is genuine and harmless.

The vulnerability that is being used was

first reported

in the wild in January, but a patch

was withdrawn

at the last moment from

Microsoft

‘s February release of patches, thus giving malware writers until tomorrow’s Patch Tuesday to exploit the flaw.

Virus Bulletin

advises users to be wary of opening unsolicited emails and to treat file attachments with extreme caution. More can be found at

Trend Micro


here

, with details on the vulnerability at

Microsoft

Security Advisory

here

.

Posted on 10 March 2008 by

Virus Bulletin