New Microsoft Outlook worm fizzles

Anti-virus vendors disappointed

A malicious version of the 'Love Bug' Outlook worm, capable of destroying data on a victim's computer, has surfaced in Europe and the US but is not expected to infect a great number of victims.

The new worm, named 'NewLove', also spreads itself through a victim's address book as its recent predecessor did. It's different, however, in that it carries a highly destructive payload, and also has some rudimentary polymorphic properties.

The subject of a message infected with NewLove starts with 'FW' and includes the name of a randomly-chosen attachment from an e-mail message on a previously infected computer. The message will have an attached file ending in .vbs, as did those sent by the Love Bug.

When a victim activates the attachment, the worm mails copies of itself to everyone in the address book. More ominously, it searches all drives connected to the host system and replaces every file with copies of itself.

Such destructiveness is one of the features preventing the worm from spreading. It disables its hosts, thereby drawing immediate attention from systems administrators. Because the Love Bug was a good deal less harmful, it was able to infect networks with far more copies of itself before the infections were discovered.

Another element slowing NewLove's spread is just plain bad social engineering. In spite of the ever-changing e-mail subject, its distribution comes too close on the heels of the Love Bug. Users are suddenly aware of worms, and can reasonably be expected to remain so for at least a few more weeks before defaulting back to their normal state of blissful ineptitude.

Releasing a worm on Thursday is also not great timing, as the weekend period of reduced computing in the workplace gives administrators a chance to clean their systems.

Finally, slapdash design in polymorphic properties causes the worm to add random text continually as it spreads so that its signature is constantly changing. But the file eventually becomes too large to be mailed, and clogs the pipes, as it were. Sheer size is not a particularly desirable trait if the goal is to gobble up bandwidth.

However, we recognise that the author had to work quickly, as Microsoft last week finally announced plans to patch Outlook so as to limit its previously splendid efficacy as a worm-launching utility. Under the circumstances, we think s/he did a fairly good job. ®

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