Microsoft acknowledged that they have known about the hole for about 4 months, while issuing the critical update for IE 5 to 8; after the attacks on Google and about 30 other companies earlier this month.
Trojan.Malscript and JS_DLoader are just some of the identified new malware scripts targeting the IE (especially IE 6) holes, which has been exposed since 20 December last year, according to Websense