Every computer connected to the internet is participating in that network and has the ability to receive malicious files. It costs nothing, literally, to run antivirus on Linux, so it is a mystery to me why some people feel that not using Linux antivirus is worth the risk. There is ample evidence of Linux malware in existence.
Indicators of compromise:
Machine is running slower than usual
Machine is consuming more power than necessary
Strange behaviour, such as installing programs without your consent, even after rebooting it.
Find these, or think you may have an infected system, or just wish to know more: