Odd entries in router logs

[#1]

I've noticed a repeated pattern in my router logs lately and I wonder if anyone might be able to shed light on it. I get pairs of entries every couple of days as follows:

LOGOUT User logged out on TELNET (IP address of my PC)

IDS scan parser : tcp syn scan: IP address of my PC scanned at least 20 ports at IP address of my router. (1 of 1) : IP address of my PC IP address of my router 0052 TCP 49693->993 [S.....] seq 1241808043 win 8192

To be clear: I never Telnet into the router myself, and no Telnet login is ever recorded in the router log, so why am I seeing a logout? And why is my PC port-scanning my router?

I've run system scans with Avast! and Malwarebytes and both have come back clean.

Can anyone suggest why I'm seeing these log entries?

[#2 · Accepted solution]

Avast! does network scans  https://blog.avast.com/2014/11/04/avast-2015-new-feature-home-network-security-scanning/

So that maybe the answer.

[#3]

Aha! That may well be it. I'll try switching Network Security off for a while just to see if the log entries stop.

Thanks!

[#4]

Turning Avast Network Security off stopped the port scanning of my router from my PC. After turning Network Security back on, the scanning resumed. So now I know it's definitely Avast and therefore benign.

Thanks for your help!