Got something in my /dev/shm

Hi!
A few days ago, I found my server had been hack, it was caused by phpbb, although I fix the hold in phpbb, but I still have these in my /dev/shm :

drwxrwxrwt 4 root root 80 Mar 24 01:36 ./
drwxr-xr-x 22 root root 118784 Oct 9 2005 ../
drwxr-xr-x 3 nobody nobody 60 May 2 08:12 .b/
drwxr-xr-x 7 nobody nobody 360 Mar 17 14:19 .dat/

in .b :
drwxr-xr-x 3 nobody nobody 60 May 2 08:12 ./
drwxrwxrwt 4 root root 80 Mar 24 01:36 ../
drwx------ 3 nobody nobody 280 May 2 08:12 emech/

in .dat :
drwxr-xr-x 7 nobody nobody 360 Mar 17 14:19 ./
drwxrwxrwt 4 root root 80 Mar 24 01:36 ../
-rwxr-xr-x 1 nobody nobody 247 Nov 13 2003 config*
-rw------- 1 nobody nobody 929 May 7 2002 config.h
-rwxr-xr-x 1 nobody nobody 341 Nov 13 2003 *****
drwxr-xr-x 2 nobody nobody 1660 Nov 9 2002 help/
-rwxr-xr-x 1 nobody nobody 202544 Nov 9 2002 httpd*
drwxr-xr-x 2 nobody nobody 80 Nov 9 2002 lang/
drwxr-xr-x 2 nobody nobody 80 Mar 16 18:44 log/
drwxr-xr-x 2 nobody nobody 60 Jul 18 2000 motd/
-rwxr-xr-x 1 nobody nobody 14306 Nov 13 2003 proc*
-rw-r--r-- 1 nobody nobody 77 Nov 9 2002 psybnc.conf
-rw------- 1 nobody nobody 6 Mar 16 18:44 psybnc.pid
-rwxr-xr-x 1 nobody nobody 64 Nov 13 2003 run*
drwxr-xr-x 3 nobody nobody 100 Nov 13 2003 scripts/
-rw------- 1 nobody nobody 139 Mar 17 14:19 ssstt
-rw------- 1 nobody nobody 139 Mar 17 14:19 ssstt.old
-rwxr--r-- 1 nobody nobody 21516 Sep 26 2002 xh*

I know these files should all be removed ASAP, but I want to know something:

1. Just delete them , right ?
2. Anything else should I check after remove these files ?

James