A developer of bulk-mail software has created pop-up spam emails using a function in the Windows messaging system.
The function was designed for use by computer network technicians to warn people on their systems of a planned shutdown.
But Zoltan Kovacs, founder of the company that makes the Direct Advertiser package, said that it can be used to make pop-up messages appear on recipients' computers in separate windows.
A worker does not even need to have a browser open to suddenly find the screen full of pop-up ads.
Kovacs explained that he designed the tool to help systems administrators send alert notices to network users more efficiently, but acknowledged that some customers have used it to launch spam attacks.
According to Wired.com, the Direct Advertiser software is the latest attempt to bypass increasingly sophisticated email filters. It also avoids state and other laws designed to curb junk email, said Kovacs.
In recent weeks, internet users have reported receiving pop-up messages including one touting university degrees without the need for classes or books.
myNetWatchman.com, which monitors some 1,400 computer networks worldwide, also detected unsolicited connection attempts of the type used by Direct Advertiser.
The software can only send text, not images or clickable links as found in pop-up ads and email.
The software finds Messenger-enabled computers by running through ranges of numeric IP addresses used to identify computers on the web.
But it may not work if a computer is behind a firewall, or if multiple computers share the same numeric address using a traffic router.
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