From the announcement:
This release provides various bugfixes, optimisations and improvements
to the scanning engine. The new features include support for ARJ and
SFX-ARJ archives, AutoIt, basic SPF parser in clamav-milter (to reduce
phishing false-positives), faster scanning and others (see ChangeLog).
To get a consistent behaviour of the anti-phishing module on all platforms,
libclamav now includes the regex library from OpenBSD.