Thursday 4 May marks the sixth anniversary of the spread of the infamous Love Bug (AKA ILOVEYOU) worm, a mass mailer that infected numerous Windows computers worldwide. Even those not infected directly found their email inboxes filed with junk, an experience that was to be repeated several times over subsequent years.
The Love Bug worm tricked users into thinking they'd received a message from a secret admirer. But if the attachment was opened on a Windows PC, the worm would leave it infected while forwarding copies of itself to email addresses harvested from compromised PCs. The suspected author of the worm, Filipino student Onel de Guzman, was arrested but escaped prosecution because of a lack of relevant laws. Laws designed to combat computer misuse in the Philippines were only introduced in June 2000 and weren't backdated, allowing de Guzman to avoid trial.
The worm used VBScripts to spread, popularising a technique that was then comparatively rare. Security experts attributed its success in spreading to its use of a love bait as an enticement, which proved to be a powerful psychological draw to bored office workers and consumers. The worm was first spotted on 3 May 2000, but its spread didn't begin in earnest until the following day, 4 May 2000.
Much has changed in the malware landscape over the intervening six years, according to UK-based net security firm Sophos. The Love Bug, and the less prolific but still virulent Melissa worm that preceded it, heralded the hay-day of mass-mailing worms that relied on social engineering to spread such attacks are now rare. Targeted Trojan and spyware attacks now represent a far greater security challenge.
In 2001, 21 per cent of all threats discovered by Sophos were Trojan horses. By April 2006 this figure had shot up to 86 per cent as hackers used Trojan horses to download malicious code, spy on users, steal information, or seize control of infected PCs. The Love Bug was conceived as a means of stealing internet connection passwords in order to give its creators cheap access to the net, making it something of a forerunner to today's menaces.
The Love Bug popularised the use of social engineering tricks to spread email worms by tricking users into double-clicking on malicious attachments. For example, the Anna Kournikova worm posed as pictures of the Russian tennis pin-up. Other malware strains offered infected files supposedly connected to Britney Spears, Paris Hilton and Jennifer Lopez.
Sophos experts say financially-motivated hackers now prefer to use Trojan horses rather than mass-mailing worms because there's a greater pay off in avoiding the public attention a major outbreak brings. Publicity about a viral epidemic tends to make users more wary, while creating a motive for police to apply more resources towards identifying culprits, an outcome cyberciminals are keen to avoid. ®