yes looks to me like hes harvested another admins cl_guidservuniq 0 guid or maybe hes used an exploit to get rcon and give himself admin before this happened.
this qvm is kinda old now and the devs for it have moved onto cQVM i suggest you try that one you might lose 1-2 things but most should be there but upgrading qvm doesn't really guarantee it wont happen again i suggest also changing rcon password and manually resetleveling admins AFTER you make sure they got cl_guidserveruniq to 1 even then if whatever exploit he used(if he didnt harvest guids) hasn't been discovered then you might be stuck with this asshole crashing your server till he gets bored or you figure out what the exploit is in which case he might just move onto the next exploit.
Edit:
Make sure all your admins have cl_guidserveruniq set to 1 (including yourself)
He was using your GUID:
1:40 ClientConnect: 3 [79.186.177.15] (858F7FF0024F9A995F09C825456C2D0D) "^4Archo^5N^7^7"
1:57 ClientDisconnect: 7 [82.45.88.17] (858F7FF0024F9A995F09C825456C2D0D) "^4{^7A^4}^7=^4S^7a^4x^7o^4n^7=^7"
nice catch didnt see that
Edit2:
could you maybe edit out the other players guid and maybe part of the ip? some people wont want them to be shown since if they dont have cl_guidserveruniq to 1 others can use their guid and cause havoc on other servers(and your players who will be banned unfairly on those servers).