I bought used Antminer L3+ and they came with a virus that steel my H/s.
Is there an anti virus that we can get to clear and reboot?
Your ASIC is a cryptojacking victim
My suggestion is completely reinstall the Latest
offical Bitmain Antminer L3+ software on your asic from SD card
Instruction how to do the firmware reloading from SD card is
HEREAfter reinstalled the software , make sure you are not using the default login information.
Also... if you have a static ip , try to change that ip somehow ,call your internet provider and ask them to assign a new IP for that location.