In Left 4 Dead 2, the "insecure" status effect can be caused by a number of things, including being near an enemy infected with the virus, being attacked by an enemy, or taking damage from a fall.
There are a few ways to fix the insecure status effect. The first is to find a first-aid kit and use it. This will immediately remove the insecure status effect.
Another way to fix the insecure status effect is to kill an enemy infected with the virus. This will also remove the insecure status effect.
Finally, you can wait for the insecure status effect to wear off on its own. This will take a few minutes, but it is the safest option.
If you are unsure of how to fix the insecure status effect, it is best to consult with a professional. Left 4 Dead 2 is a challenging game, and it is important to be as prepared as possible.