To be honest, I really have no clue.
Code:
24 2 * * * /scripts/upcp
0 1 * * * /scripts/cpbackup
*/15 * * * * /usr/local/cpanel/whostmgr/bin/dnsqueue > /dev/null 2>&1
2,58 * * * * /usr/local/bandmin/bandmin
0 0 * * * /usr/local/bandmin/ipaddrmap
0 6 * * * /scripts/exim_tidydb > /dev/null 2>&1
16 21 * * * /usr/local/cpanel/whostmgr/docroot/cgi/cpaddons_report.pl --notify
*/5 * * * * /usr/local/cpanel/bin/dcpumon >/dev/null 2>&1
Could be one of those Cpanel scripts doing it I suppose. I will have to look into them. I find it odd that the wtmp would ever need to be cleaned though...