Bypasses are for specific games that use anti-cheats that block WeMod and other cheating applications.
These may be needed at any time the game’s developers add anti-cheat. In the case of Phasmophobia, as an example, they added an anti-cheat that crashes the game when WeMod is detected in the background, which was not present for a while.
The bypass file does not contain any viruses. Anti-viruses don’t like it because there’s code within the bypass that changes other code in another application to allow a certain application (aka WeMod) through, so they consider it a trojan.
Hope this helps explain why bypasses may be needed for games, and why it is falsely flagged as a trojan. To fix it, you need to temporarily disable the anti-virus, download the bypass, add it as an exception to your anti-virus, then re-enable your anti-virus.