A vulnerability has been exposed by Microsoft that affects various versions of windows software.
The attacks are targeted and can only be successful with user involvement, the document or link that the malicious file resides must be knowingly opened by the user for the hack to be successful.
The flaw affects TIFF files (Tagged Image File Format) used widely in the graphics and design industries. Hackers send a document or link containing the flawed image which when opened allows them to gain access to the users computer.
The programs affected include Windows Vista, Server 2008, Microsoft Office 2003 to 2010 and Microsoft Lync.
Microsoft are working to address the issue, with a fix expected in their next monthly security bulletin due next Tuesday, if not before.