As computer users learned from the Melissa virus, malware often arrives as a wolf in sheep’s clothing: a commonplace file such as a Word doc or Excel spreadsheet. But Melissa—the scourge of spring 1999—was not the first such “macro virus” to hit users. That’s thought to be the aptly named Concept, which was reportedly shipped to hundreds of users in August 1995 on a CD-ROM labeled “Microsoft Compatibility Test.”
A macro virus like Concept or Melissa is written in the same macro language as a program such as Word or Excel and infects documents and templates—not programs themselves. The malware is generally spread via email attachment. Once the infected attachment is opened, the virus starts running, potentially infecting other files and damaging the operating system—and often emailing itself out to recipients in your email address book, taking advantage of some insidious social engineering.
Concept macro virus wasn’t overly damaging
The Concept macro virus infected files that were saved using the “Save As” command on Word 95. Its only symptom was the error message displayed once a document was infected. Other macro viruses, though, have been far more harmful.
Microsoft lists several signs your device might be infected with a macro virus: unexpected prompts for passwords, unusual dialog box messages, words moving or being mysteriously inserted in your documents, or missing menu items. Another way to tell if you’ve been infected: Check the macros installed on your computer for unusual entries, such as AAAZAO, AAAZFS, AutoOpen, FileSaveAs, and PayLoad.
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