Trend Micro has upgraded its alert for WORM_NETSKY.C to a
'high risk' alert to raise awareness among users of this worm, which has a high spread potential and employs several techniques to avoid detection.

WORM_NETSKY.C arrives in a common-sounding file attachment, with brief subject and message lines mimicking a possible message from a known source.

Attachment names, subject and message lines seem to vary from previous variants, suggesting that the creator may be trying perfect a blend of key words and phrases that fool users into opening the worm - relying on an old but effective trick.

Attachments may also bear an icon similar to those used by Window's programs to appear authentic to the recipient. This worm
is also capable of arriving in a "zipped" or compressed file.

Once executed, WORM_NETSKY.C collects addresses from the infected machine's files, but purposely skips those related to certain security vendors and organisations, to avoid making itself known to those who could combat it.

Customers of Trend Micros Outbreak Prevention Services should download OPP 85 (number 781) to help protect against spread of this threat, while subscribers to its Damage Cleanup Services, Damage Cleanup template # 268 is available for help with automated restoration of affected systems.