According to Microsoft, the security vulnerability affects all versions of Internet Explorer from v6.x upwards on all Windows NT-based operating systems (Windows 2000, XP, Vista, Windows 7). Put simply, Infosecurity notes, every Windows user who might be affected should install it.

The original exploit only worked if people were running Internet Explorer 6 on Windows XP, but now the exploit code has been published, some malware writers are rumoured to be adapting the code for a wider target market.

Some good may come out of the saga, which started earlier in the month when the Gmail accounts of a number of anti-China dissidents were hacked – and came to a head earlier this week with the French and German governments recommending that their citizens use a web browser other than Internet Explorer.

According to a report in the Wall Street Journal the saga has resulted in downloads of Mozilla Firefox and Opera taking off into the stratosphere.

The WSJ says that German downloads of Firefox "spiked in the four days following the Friday posting of the recommendation by the German agency", with 300 000 incremental downloads above its normal rate.

Opera, meanwhile, is said to have benefited from the advice from the French and German governments to switch from Internet Explorer, with downloads doubling over the weekend and the following days.