The Internet has opened the door to creators of malicious code looking to profit from fraud and identity theft and Trojans and spyware are their favored weapons, as they can be easily concealed on users' computers.
Adware and spyware, responsible for nearly 40 percent of detections in total, topped the 2006 ranking. Both types of malware are advertising-related, as they collect private data from infected users, including information on Web sites viewed or online stores used. The data is then used to tailor advertising to users' preferences. This activity is of dubious legality, since it is carried out without the user's consent.
Trojans were the culprits in 17 percent of detections, rising nearly 10 points in the last quarter in comparison to the previous quarter. This particularly dangerous type of malware can operate while remaining undetected on infected systems. Presently, its main purpose is the theft of passwords used for financial operations, in order to gain unauthorized access to users' bank accounts.
Other malware detected in 2006 included dialers, responsible for 7.5 percent of detections, followed by backdoor Trojans (5.6 percent), and bots and worms, both at 3.8 percent. None of these figures varied significantly during 2006.
