clamav & .sim directories in /tmp

Hello,

I have several clamav??? and .sim-??? directories and mysql files in my /tmp directory of our server.

exemples:

total 2432
drwxrwxrwt 49 root root 54272 Sep 8 13:25 ./
drwxr-xr-x 23 root root 4096 Sep 8 11:35 ../
drwxr-xr-x 2 root root 1024 Sep 8 11:28 .sim-14988/
drwxr-xr-x 2 root root 1024 Sep 6 17:26 .sim-21410/
drwxr-xr-x 2 root root 1024 Sep 6 17:31 .sim-21760/
drwxr-xr-x 2 root root 1024 Sep 6 17:32 .sim-22303/
drwxr-xr-x 2 root root 1024 Sep 6 17:36 .sim-22929/
drwxr-xr-x 2 root root 1024 Sep 6 11:55 .sim-23003/
drwxr-xr-x 2 root root 1024 Sep 6 11:55 .sim-23081/

....

-rw------- 1 mysql mysql 0 Sep 6 08:12 MY4s1IPj
-rw------- 1 mysql mysql 0 Sep 6 08:12 MY5v7OES
-rw------- 1 mysql mysql 0 Sep 6 08:12 MY8XMAvK
-rw------- 1 mysql mysql 0 Sep 6 08:12 MYC6hC4E
-rw------- 1 mysql mysql 0 Sep 6 08:12 MYI82h68
-rw------- 1 mysql mysql 0 Sep 6 08:12 MYIp4EBd
-rw------- 1 mysql mysql 0 Sep 5 12:29 MYLs2MVN
-rw------- 1 mysql mysql 0 Sep 6 08:12 MYMJ7bf6
-rw------- 1 mysql mysql 0 Sep 6 08:12 MYPS2vu8


drwx------ 2 root root 1024 Sep 6 13:04 clamav-00e7d887da675454/
drwx------ 3 root root 1024 Sep 7 22:57 clamav-028fcd300561782f/
drwx------ 2 root root 1024 Sep 6 13:03 clamav-03416ea095195eed/
drwx------ 2 root root 1024 Sep 6 15:59 clamav-0ea004fb2b0b8ca4/
drwx------ 3 root root 1024 Sep 7 22:56 clamav-1ba5842343d38781/
drwx------ 2 root root 1024 Sep 6 13:20 clamav-1d2858211e34de87/

What are they ?
Who's putting them over there ?
May I delete them ?
is it possible to delete them automatically ?

Thanks for yur help.

 

What do I need to change in this file so that it will delete the files in /tmp sooner ?

/usr/sbin/tmpwatch 240 /tmp
/usr/sbin/tmpwatch 720 /var/tmp
for d in /var/{cache/man,catman}/{cat?,X11R6/cat?,local/cat?}; do
if [ -d "$d" ]; then
/usr/sbin/tmpwatch -f 720 $d
fi
done

Thanks allready for you help.