Firms wait for Microsoft fix for day zero PowerPoint flaw.

Experts at Sophos have advised companies to exercise care over which PowerPoint presentations their users open, as businesses wait for Microsoft to fix an unpatched PowerPoint vulnerability. Microsoft has confirmed that a critical vulnerability exists in PowerPoint 2000, PowerPoint 2002 and PowerPoint 2003 which can allow malicious attackers to run unauthorized code on users' computers. According to the company, it is scheduled to issue a fix on Tuesday 8 August or earlier if required.

"Once a PC has been infected by a backdoor Trojan, hackers can gain access to the computer to spy, to steal, to plant further malicious software, or to launch spare and/or denial-of-service attacks. Many eyes will now be looking to Microsoft, to see how quickly they can release a critical security fix for their PowerPoint program," continued Cluley. "Everyone needs to exercise caution over which files they choose to open on their Windows PC."

Last week, Sophos experts of a malicious Chinese PowerPoint PPT file which contained exploit code that drops the keylogging Trojan horse onto users' computers.

The Trojan horse also attempts to disable anti-virus products running, then secretly drops a Trojan horse onto the computer. Sophos has been protecting against the Troj/Edepol-C Trojan horse dropped by the Microsoft PowerPoint file since 14:01 GMT, Friday 14 July, but warns that hackers could exploit the PowerPoint vulnerability to spread new TroJan horses.

www.sophos.com