The automated microupdates appear to have replaced the pop3login file yesterday and since that time the server's been logging thousands of these:
pop3login[10300]: segfault at 0 ip 00007f83b827d59f sp 00007fff6a65cbd8 error 4 in libc-2.12.so[7f83b814b000+189000]
pop3login[11855]: segfault at 0 ip 00007fa9abce859f sp 00007fff6bbd0a08 error 4 in libc-2.12.so[7fa9abbb6000+189000]
pop3login[13411]: segfault at 0 ip 00007fa10245359f sp 00007fff0d3f81b8 error 4 in libc-2.12.so[7fa102321000+189000]
pop3login[21237]: segfault at 0 ip 00007f585d6ff59f sp 00007ffffbab15e8 error 4 in libc-2.12.so[7f585d5cd000+189000]
pop3login[22896]: segfault at 0 ip 00007f64cbd8759f sp 00007fff37c54e48 error 4 in libc-2.12.so[7f64cbc55000+189000]
pop3login[24515]: segfault at 0 ip 00007f743e79159f sp 00007fff396ad188 error 4 in libc-2.12.so[7f743e65f000+189000]
pop3login[26539]: segfault at 0 ip 00007f6dfeea759f sp 00007fff8737ebb8 error 4 in libc-2.12.so[7f6dfed75000+189000]
This is a CentOS 6 x86_64 server with Plesk 10.4.4.
pop3login[10300]: segfault at 0 ip 00007f83b827d59f sp 00007fff6a65cbd8 error 4 in libc-2.12.so[7f83b814b000+189000]
pop3login[11855]: segfault at 0 ip 00007fa9abce859f sp 00007fff6bbd0a08 error 4 in libc-2.12.so[7fa9abbb6000+189000]
pop3login[13411]: segfault at 0 ip 00007fa10245359f sp 00007fff0d3f81b8 error 4 in libc-2.12.so[7fa102321000+189000]
pop3login[21237]: segfault at 0 ip 00007f585d6ff59f sp 00007ffffbab15e8 error 4 in libc-2.12.so[7f585d5cd000+189000]
pop3login[22896]: segfault at 0 ip 00007f64cbd8759f sp 00007fff37c54e48 error 4 in libc-2.12.so[7f64cbc55000+189000]
pop3login[24515]: segfault at 0 ip 00007f743e79159f sp 00007fff396ad188 error 4 in libc-2.12.so[7f743e65f000+189000]
pop3login[26539]: segfault at 0 ip 00007f6dfeea759f sp 00007fff8737ebb8 error 4 in libc-2.12.so[7f6dfed75000+189000]
This is a CentOS 6 x86_64 server with Plesk 10.4.4.