Messaging spam, sometimes called spim, is a type of spamming where the target is instant messaging services.
Instant messaging (IM) systems are a popular target 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. To combat this, some users choose to receive IMs only from people they already know.
In 2002, a number of spammers have begun using the Microsoft Windows Messaging service to get their message across. This isn't the same as the IM system "MSN Messenger"; rather, it is a function of Windows designed to allow servers to send alerts to administrator workstations. Windows Messaging spam appears as normal dialog boxes containing the spammer's message. Windows Messaging spam can be delivered using any NetBIOS port, so to block it at a firewall entails closing down ports 135 through 139, and 445.
The increase in messaging spam may be motivated by its rise in popularity as well as the many steps to crack down on spamming since the late 1990s.
<center>This article is part of the Spamming series.
