Do antivirus companies create computer viruses?

No. Antivirus companies know the risks involved when dealing with computer viruses and the potential dangers of viruses getting out in the wild. The whole concept of antivirus companies creating viruses is a myth, urban legend, and a conspiracy theory.

Creating viruses would increase profits

There are plenty of viruses and other malware to justify the needs of antivirus programs. If antivirus companies believed that distributing viruses would help increase profits or sales, they would create viruses and other malware for other platforms. Such as the Apple Macintosh and *nix where virus threats are not as high with Microsoft Windows users.

Antivirus companies are better at increasing their profits if they can keep their products up-to-date at detecting, and cleaning all computer viruses and other threats.

Where is the proof that antivirus companies don't create viruses?

1. Creating computer viruses is not that difficult for someone familiar with computers and programming. Creating viruses would not help in the detection or prevention of viruses.
2. An antivirus company couldn't protect itself from the virus before it was released without raising suspicion. Therefore, it would infect its own product, causing customer dissatisfaction.
3. There are plenty of other users who are not affiliated with antivirus companies who already create viruses and other malware.
4. The code that makes up a virus is reviewed by several security experts when a virus gets out in the wild. Analyzing that code could trace its origins back to the antivirus company.
5. An antivirus company could be held liable for creating viruses, which would not only make the company look bad but would also result in lawsuits.
6. Since 1988, when researchers began to think about and create antivirus solutions, there hasn't been a report of a security company creating viruses.

I'm sure an antivirus company hires virus writers

No. Again an antivirus company doesn't want to be affiliated with someone who may have caused a person or company a loss of data or money. Regardless of how skilled an individual may be at writing viruses.