Microsoft has updated its critical security advisory on Excel, put out on its July 10 Patch Tuesday, to include Office 2004 for Mac.

Microsoft's MS07-036 advisory covers three critical Excel bugs, all remotely exploitable.

This isn't a patch to ignore, security analysts say, given that vulnerable systems can be taken with a Trojan.

"Vulnerabilities in Office applications have been a favorite attack method among cybercrooks," Dave Marcus, security research and communications manager at McAfee Avert Labs, said in a statement on Patch Tuesday. "Trojan horse attacks often use rigged Office files that exploit vulnerabilities in the productivity applications."