McAfee was forced to rush out an anti-virus signature
update last Friday (10 March) after its desktop security update
started to try and quarantine Microsoft Excel and other
applications.
As a result of the mistake Excel, Adobe Update Manager and other
applications were wrongly marked as a virus called W95/CTX,
admitted McAfee.
McAfee said about 100 companies and individual users notified it
of the problem, after seeing their legitimate applications marked
as viruses by the company.
McAfee said corporate users received updated virus definition
signatures within two hours of the wrong ones being identified.
Such mistakes by anti-virus engines are called “false positives”
and are not as rare as some users would imagine.
It is rare, however, that established applications such as Excel
would be wrongly marked as threats.
The problem can often affect custom-made applications or very
new ones which have not been dealt with by anti-virus scanning
engines before.
The McAfee problem only affected desktop versions of the
anti-virus software and not server-based systems.