Messaging spam

(Spam Twitter)-Messaging spam, sometimes called SPIM, is a type of spam targeting users of instant messaging (IM) services.

Messenger Service spam on Windows NT-based systems

In 2002, a number of spammers began abusing the Messenger Service, a function of Windows designed to allow administrators to send alerts to users' workstations (not to be confused with Windows Messenger or Windows Live Messenger, a free instant messaging application) in Microsoft's Windows NT-based operating systems. Messenger Service spam appears as normal dialog boxes containing the spammer's message. These messages are easily blocked by firewalls configured to block packets to the NetBIOS ports 135-139 and 445 as well as unsolicited UDP packets to ports above 1024.Additionally, Windows XP Service Pack 2 disables the Messenger Service by default.

Instant messaging applications

Instant messaging systems, such as Yahoo! Messenger, AIM, Windows Live Messenger, Tencent QQ, ICQ, XMPP and Myspace chat rooms, are all targets for spammers. Many IM systems offer a directory of users, including demographic information such as age and sex. Advertisers can gather this information, sign on to the system, and send unsolicited messages, which could include commercial scam-ware, viruses, and links to paid links for the purpose of click fraud. Microsoft has announced that the upcoming Windows Live Messenger 9.0 would support specialized features to combat messaging spam. In most systems users can already block the vast majority of spam through the use of a whitelist.

Countermeasures

Many users choose to receive IMs only from people already on their contact list.

In corporate settings, spam over IM is blocked by IM spam blockers like those from FaceTime Communications, Akonix, ScanSafe, Symantec, and CSC