This category is a variant of the saboteurs. Whether for personal gain or out of plain mean-mindedness, these difficult people at work will sell you down the river. They are usually pleasant and co-operative on the surface. This enables them to obtain inside information and then act on it. Here are some symptoms of a backstabber in your office:

• A personal confidence that damages your professional image at the workplace is leaked to the authorities.
• The fact that you have under-performed or made a serious mistake is suddenly the talk of the office.
• Someone else gets the credit for a project that you slaved on. Amongst the difficult people at the workplace, these can be the most damaging.

This article is part of the Difficult people at work series.