A leading Chinese anti-virus company said on Monday that ten thousand computers nationwide were affected by a new MSN virus.

The worm virus uses MSN to send compressed files, named "Photo" or "Picture". It will first send an invitation messenger, like "you and me, look at it" or "Please receive my photo" in Pinyin. Once the compressed files are downloaded, the computer system will break down.

Experts warn people to identify MSN senders before receiving or downloading any file, and at the same time to upgrade their antivirus system regularly.