Damned if you do, damned if you don't
Insecurity experts have been hassling Microsoft over the
use of white lists. Microsoft has been recommending that users exclude some
file extensions and folders from antivirus scans, because it thinks that they
will be safe. Having a scanner look at all files takes a lot of time
and mostly pointless, Redmond thinks.
In a document published on its support site, Microsoft
suggests that users do not scan some files and folders for malware as a way to
improve performance in Windows 2000, XP, Vista, Windows 7, Server 2003, Server 2008 and Server 2008 R2.
"These files are not at
risk of infection. If you scan these files, serious performance problems may
occur because of file locking," Microsoft states in the document However
security experts say that is the sort of attitude that gets computers infected
and Microsoft may be putting users at risk. Among the files and folders Microsoft tells users to
exclude are those associated with Windows Update and Group Policy, and files
with the .edb., .sdb and .chk extensions contained within the
Trend Micro said that while the list was ok it should
never have been made public. David Sancho, a malware researcher with Trend Micro, in
an entry to his firm's blog claimed that the list could be a boon to hackers.
"Cybercriminals may strategically drop or download a
malicious file into one of the folders that are recommended to be excluded from
scanning, or use a file extension that is also in the excluded list," he