Researchers at Symantec
said late Tuesday they've spotted a Web site that tries to exploit computers
lacking one of the recently
issued patches for versions of Microsoft's Excel spreadsheet program.
The vulnerability involves a malicious Excel file that when opened can allow
a hacker to execute other code on a PC.
In its advisory, Symantec said one Web server is hosting the malicious file,
which it calls "Trojan.Mdropper.AA." The Trojan Horse spreadsheet
document can download other harmful files to a computer.
Users could become infected if they open the malicious Excel file sent to them
as an e-mail attachment. Also, they could be redirected to the Web site hosting
the file by an iframe embedded in a page on a compromised Web site, the vendor
said.
To protect computers, users are advised to apply MS08-014,
the batch of patches Microsoft released earlier in the month that fixes several
flaws in Excel 2000, 2002, 2003 and 2007 for Windows. Administrators should
also block their users from accessing "intop.info," the site hosting
the file.
On March 11, Microsoft released four critical updates that fixed 12 vulnerabilities
for its Excel, Outlook, Office 2000 and Office's Web components.
