• Never open, accept, or download a file in IM from someone you don't know.
• If the file comes from someone you dont know, don't open it unless you know what the file is.
• Contact the sender by e-mail, phone, or some other method to confirm that what they sent was not a virus.
• Visit Microsoft Update to scan your windows computer and install any high-priority updates that are offered to your PC.
• If you have Automatic Updates enabled, the updates are delivered to you when they are released, but you have to make sure you install them.
• Similarly, the concern software patches from Linux OS also need to be updated
Use up-to-date version of your Instant Messenger software for a better protection of your computer against viruses and spyware.
• If you're using MSN Messenger, upgrade to Windows Live Messenger, which will block attachments that might contain malware and allow you to scan attachments for viruses.
• Similarly for other Instant Messengers like yahoo, AOL should be upgraded.
• Like e-mail viruses, instant message viruses are malicious programs that are designed to travel through IM.
• Spim is a short form of spam over instant messaging, it uses IM platforms to send spam messages over IM.  Like e-mail spam messages, a spim message also contains advertisements. It generally contains web links, by clicking to on those links malicious code enters into your PC.
• Antivirus software can help to detect and remove IM viruses from your computer, only if you keep the antivirus software up-to-date.
• If you've purchased a subscription from an antivirus software company, your antivirus software may update itself when you're connected to the Internet.
• Antispyware software can help to protect your computer from spyware and remove any spyware you may already have.
• If you don't have antispyware software, you can download Windows Defender.