Back in 2005, a hacker named Carlos Enrique Perez-Melara released a piece of malware called "Loverspy" into the world. The $89 software purported to be a way to catch a cheating lover — it sent the suspected cheater an electronic greeting card that, when opened, would install a particularly malicious Trojan that could capture keystrokes, email addresses, instant messages, and even record video from a webcam. Once it was installed, the infected computer was essentially at the attacker's mercy. Now, more than than eight years after being indicted in July 2005, the FBI has added Perez-Melara to its most wanted list of cybercriminals.
As noted by the Associated Press, Perez-Melara is a bit of an anomaly compared to the other criminals on the FBI's list. It doesn't appear that Perez-Melara made a significant amount of money from his malware — unlike other members of the FBI list who allegedly stole significant cash from their victims. However, Loverspy was noteworthy for the level of access it gave users to its victims' machines: the program was designed "with stealth in mind, claiming that it would be impossible to detect by 99.9 percent of users," said the July 2005 federal indictment. All told, the software was purchased by 1,000 customers, who then tried to infect a total of 2,000 victims —the FBI said that victims took the bait about half the time.
Pereze-Melara has also been notoriously difficult to catch, a major reason behind the FBI adding him to their most-wanted list. He's been in hiding since his indictment; El Salvador was his last known location. The FBI's offering $50,000 for information leading to his arrest.