리눅스 이상현상..ㅡ.ㅡ; 해결부탁드려요~

래드햇 리눅스를 사용하다가 이상하게 몇일전부터 이러더군요..

/root 와 /root/bin 디렉토리에서 아래와 같은 이상 현상이 나타나네요..

[root@RedHat_Linux bin]# cd /root
[root@RedHat_Linux root]# ls
 ??echo    ?        echo "[list] ?> " ???echo   anaconda-ks.cfg  bin  dead.letter  install.log  install.log.syslog  mbox
[root@RedHat_Linux root]# cd /root/bin
[root@RedHat_Linux bin]# ls
?        echo                              system_check_command   system_check_gdiskio     system_check_index
?        echo "[list] ?> "??        echo   system_check_cpu       system_check_ginterrupt  system_check_main
conf                                       system_check_crontab   system_check_gload       system_check_modify
help                                       system_check_disk      system_check_gmemory     system_check_port
log                                        system_check_firewall  system_check_gnetwork    system_check_process
system_check                               system_check_gcpu      system_check_gprocess    system_check_system_file
system_check_backdoor                      system_check_gdisk     system_check_graph       system_check_user
[root@RedHat_Linux bin]#

shell로 뭐 좀 하다가 생긴것 같은데.. 왜 이런게 생기는건지.

해결좀해주세요~~