Cyber extortion targets office workers.

In London, cyber blackmail artists looking to make an easy pound are threatening office workers via e-mail. Police said the criminals threaten to delete computer files or install pornographic images on an employee's PC unless he or she pays them a ransom.

The extortion seam indiscriminately targets anyone on the corporate ladder with a PC connected to the Internet. It starts with a cryptic e-mail in which the author claims to be able to take over a worker's computer through an opening in the corporate network, investigators said. The e-mail typically demands that unless a small fee is paid--usually $20 or $30--they will attack the PC with a file-wiping program or download images of child pornography onto the machine.

Because the ransom is small, people tend to pay up and keep quiet. But British detectives advise against cooperating with the con artists because doing so may encourage them to come back for more.

The London case is not isolated. In fact, crime gangs are turning cyber extortion into big business worldwide. According to Finnish computer security firm F-Secure, a large Scandinavian university was hit in January when several school officials received an e-mail from an individual who appeared to be based in Estonia. The e-mail said that several security vulnerabilities had been detected on the university's network and that unless the e-mail recipient transferred 20 euros ($25 U.S.) to the author's online bank account, he would release a series of viruses capable of deleting computer files. F-Secure managers urged the university to take the necessary precautions, notify police, and not pay. But in some cases, the threat was no bluff, and the perpetrators have launched denial-of-service attacks on a company's network, capable of crippling it with an overwhelming flood of data. Either way, even if only a handful of victims send the requested money, the scheme has been profitable for the scare artist.

While experts say such cyber crimes are difficult to solve, it may not be impossible. Computers not only provide the means of committing crime, they can also provide essential evidence of a crime. Electronic records such as computer network logs, e-mails, word-processing files, and picture files increasingly provide important evidence in criminal cases. The European Union Cyber Tools Online Search for Evidence (CTOSE) project has developed a methodology that identifies, secures, integrates, and presents electronic evidence. It enables anyone--system administrators, information technology staff, police, and investigators--to follow standardized procedures when investigating computer incidents using forensic tools to legally and properly gather and preserve all electronic evidence. The evidence will stand up in any court or tribunal proceedings throughout Europe.