Four Microsoft Advisories to cover this month, fortunately, one of them was released in December so that left three...

Microsoft Security Advisory MS09-002:
Microsoft Internet Explorer contains programming errors that may allow a remote attacker to execute code on a vulnerable system.

Rules to detect attacks targeting these vulnerabilities are included in this release and are identified with GID 3, SIDs 15304 and 15305.

Microsoft Security Advisory MS09-003:
Microsoft Exchange contains programming errors that may allow a remote attacker to execute code or cause a Denial of Service (DoS) on an affected system.

Rules to detect attacks targeting these vulnerabilities are included in this release and are identified with GID 3, SIDs 15301 and 15302.

Microsoft Security Advisory MS09-004:
A vulnerability in Microsoft SQL Server may allow a remote attacker to execute code on a vulnerable system. This issue may be exploited via the sp_replwritetovarbin stored procedure.

Rules to detect attacks targeting these vulnerabilities were included in a previous release and are identified with GID 1, SIDs 15127 through 15144.

Microsoft Security Advisory MS09-005:
Microsoft Visio contains programming errors that may allow a remote attacker to execute code on a vulnerable system via malformed Visio files.

Rules to detect attacks targeting these vulnerabilities are included in this release and are identified with GID 3, SIDs 15298, 15299 and 15303.

Details and rules are available here: http://www.snort.org/vrt/advisories/vrt-rules-2009-02-10.html