A flaw in Windows versions of Photoshop could make systems vulnerable.
A security flaw has appeared in
Adobe’s License Management Service, which handles product activation
for Photoshop CS, Creative Suite 1.0 and Premier Pro 1.5. It does not
affect the Creative Suite 2.0. The flaw potentially allows access to
the user’s computer by someone exploiting the flaw.
Adobe have commendably already issued a patch, so if you have these versions, on Windows only, you should download the patch.