I have tweeted about this before but now Google has started to warn about it. Scareware is where a malicious piece of software disguises itself as a normal program but then demands money from you otherwise your something will happen.
I have always seen the fake anti virus ones that pop up and can not be closed down, they say your computer is infected and unless you pay a set fee to buy this program then they will not remove anything. The truth is that program is the malicious code and often adds other malicious programs which, even if you did pay, it would not remove them. The name of this program changes every so often, one was called anti virus 2009.
Anyway back to Google, they scanned 240 million web pages over 13 months, January 2009 to February 2010, and found that fake anti virus programs accounted for 15% of all malicious software. Over 11,000 web domains were involved in the distribution of the fake anti virus software. This attack is mainly aimed at Windows machines and is usually delivered through ADVERTS. The reason I highlighted adverts is I often get asked if it was because someone in the household had been on ‘adult’ sites, while some will be on adult sites most are now using normal looking website so they can get a greater infection.
It’s really great that people are sharing this inofrtamion.