Using websites like Facebook and Twitter without an antivirus program can be dangerous, and many who clicked on a link that appeared to lead to CNN's website may have realized this. The link said "U.S. attacks Iran and Saudi Arabia, the begin of World War 3," but instead leads users to a malware download.
When the supposed Flash upgrade is downloaded, the user's computer is infected with a Trojan horse virus. At least 60,000 people have clicked this link and been infected with this virus thus far, sources say.
The particular malware in this case is the Troj/Rookit-JV virus and is part of a trend of hackers and others posting fake links that lead to virus infections on Facebook. The supposed video on the fake link is said to have shown footage of the United States attacking both Iran and Saudi Arabia.
It may seem like common sense to stay away from links like this, but it is never known how sophisticated these attacks will get, so internet security software should always be installed and ready to go.