
The flaw is being used to distribute the Keylogger.DB Trojan which is designed to steal confidential data by logging keystrokes.
PandaLabs said that this is a similar security problem to that discovered a few months back, categorised as CVE-2007-6026, but the new flaw also affects the msjet40.dll library, albeit at a different point.
Luis Corrons, technical director of PandaLabs, said: "Whenever a vulnerability of this type appears cyber-crooks will try to take full advantage.
"We can therefore expect to see more malicious Access files in circulation that contain this Trojan and other types of threat."