Microsoft has released a bug workaround to temporarily fix a flaw in ActiveX.
The fix is to counter a vulnerability in the Snapshot Viewer ActiveX control for Microsoft Access, which the computer giant admitted hackers have been trying to target.
The flaw affects the Snapshot Viewer in Microsoft Office Access 2000, 2002 and 2003.
Microsoft says that attacks have included tricking users into visiting sites containing rogue ActiveX controls designed to exploit the vulnerability.
If this approach works, it seems that the hacker can get the same rights as logged-on users to compromised machines.
Microsoft is still trying to fix the problem but in the meantime, has suggested a range of measures users can take to protect their machines.
Some of these involve preventing COM objects from running in Internet Explorer, or disabling scripting.
The Register adds: "The first of these means using the Registry Editor, where mistakes can really screw up your system, while the second might leave users unable to use many websites normally".
The website also recommends Windows users might want to use Firefox or Opera until a proper fix is issued by Microsoft.