It has emerged that some earlier versions of McAfee's anti-virus had security flaws that could have led to hackers compromising systems which had the software installed. Security experts at ISS have confirmed a flaw in the software when it tries to process LHA files in anti-virus library. ISS believes that an exploit crafted for this flaw could lead to unauthorised access to networks and machines being protected by the McAfee Anti virus Library product. Versions of the software prior to the 4400 version are affected.