SpamAssassin 3.4.3 has been released. It includes a new plugin for finding
macros in Office documents, a couple of security fixes, and various other
improvements. The project is also letting it be known that, due to the
dropping of support for rulesets with SHA-1 signatures, versions of
SpamAssassin prior to 3.4.2 will no longer be able to download rule updates
as of the beginning of March.

Source: LWN.net – SpamAssassin 3.4.3 available