几天前，我在我的ubuntu 16.04中安装了shellinabox，因为我不再使用它，所以我通过sudo apt-get remove shellinabox卸载它。卸载成功后，我检查了进程，发现shellinabox进程仍然存在，如果我杀了这个进程，几秒钟后，它再次显示。
ldh@ldh55:~$
ldh@ldh55:~$ ps -ef|grep shellinabox
ldh 5178 10185 0 14:10 pts/21 00:00:00 grep --color=auto shellinabox
nobody 113899 113881 0 13:56 ? 00:00:00 shellinaboxd -t -s /:LOGIN -s /python:shell:shell:HOME:/usr/bin/python -s /ipython:shell:shell:HOME:/usr/bin/ipython -s /python3:shell:shell:HOME:/usr/bin/python3 -s /ipython3:shell:shell:HOME:/usr/bin/ipython3 -s /cling:shell:shell:HOME:/usr/local/bin/cling --static-file=styles.css:/usr/local/share/shellinabox/shellinabox.css --user-css=Tomorrow Light:+/usr/local/share/shellinabox/theme-tomorrow-light.css,Tomorrow Dark:-/usr/local/share/shellinabox/theme-tomorrow-dark.css
nobody 113990 113899 0 13:56 ? 00:00:00 shellinaboxd -t -s /:LOGIN -s /python:shell:shell:HOME:/usr/bin/python -s /ipython:shell:shell:HOME:/usr/bin/ipython -s /python3:shell:shell:HOME:/usr/bin/python3 -s /ipython3:shell:shell:HOME:/usr/bin/ipython3 -s /cling:shell:shell:HOME:/usr/local/bin/cling --static-file=styles.css:/usr/local/share/shellinabox/shellinabox.css --user-css=Tomorrow Light:+/usr/local/share/shellinabox/theme-tomorrow-light.css,Tomorrow Dark:-/usr/local/share/shellinabox/theme-tomorrow-dark.css
ldh@ldh55:~$
ldh@ldh55:~$ kill -9 113899
-bash: kill: (113899) - Operation not permitted
ldh@ldh55:~$ sudo !!
sudo kill -9 113899
ldh@ldh55:~$ ps -ef|grep shellinabox
ldh 5637 10185 0 14:10 pts/21 00:00:00 grep --color=auto shellinabox
ldh@ldh55:~$
ldh@ldh55:~$ ps -ef|grep shellinabox
ldh 5754 10185 0 14:10 pts/21 00:00:00 grep --color=auto shellinabox
ldh@ldh55:~$ ps -ef|grep shellinabox
nobody 5693 5675 1 14:10 ? 00:00:00 shellinaboxd -t -s /:LOGIN -s /python:shell:shell:HOME:/usr/bin/python -s /ipython:shell:shell:HOME:/usr/bin/ipython -s /python3:shell:shell:HOME:/usr/bin/python3 -s /ipython3:shell:shell:HOME:/usr/bin/ipython3 -s /cling:shell:shell:HOME:/usr/local/bin/cling --static-file=styles.css:/usr/local/share/shellinabox/shellinabox.css --user-css=Tomorrow Light:+/usr/local/share/shellinabox/theme-tomorrow-light.css,Tomorrow Dark:-/usr/local/share/shellinabox/theme-tomorrow-dark.css
nobody 5758 5693 0 14:10 ? 00:00:00 shellinaboxd -t -s /:LOGIN -s /python:shell:shell:HOME:/usr/bin/python -s /ipython:shell:shell:HOME:/usr/bin/ipython -s /python3:shell:shell:HOME:/usr/bin/python3 -s /ipython3:shell:shell:HOME:/usr/bin/ipython3 -s /cling:shell:shell:HOME:/usr/local/bin/cling --static-file=styles.css:/usr/local/share/shellinabox/shellinabox.css --user-css=Tomorrow Light:+/usr/local/share/shellinabox/theme-tomorrow-light.css,Tomorrow Dark:-/usr/local/share/shellinabox/theme-tomorrow-dark.css
ldh 5792 10185 0 14:10 pts/21 00:00:00 grep --color=auto shellinabox
ldh@ldh55:~$
ldh@ldh55:~$ sudo ls -l /proc/5693/
total 0
dr-xr-xr-x 2 nobody nogroup 0 Sep 5 14:11 attr
-rw-r--r-- 1 root root 0 Sep 5 14:11 autogroup
-r-------- 1 root root 0 Sep 5 14:11 auxv
-r--r--r-- 1 root root 0 Sep 5 14:10 cgroup
--w------- 1 root root 0 Sep 5 14:11 clear_refs
-r--r--r-- 1 root root 0 Sep 5 14:10 cmdline
-rw-r--r-- 1 root root 0 Sep 5 14:11 comm
-rw-r--r-- 1 root root 0 Sep 5 14:11 coredump_filter
-r--r--r-- 1 root root 0 Sep 5 14:11 cpuset
lrwxrwxrwx 1 root root 0 Sep 5 14:11 cwd -> /home/shell
-r-------- 1 root root 0 Sep 5 14:10 environ
lrwxrwxrwx 1 root root 0 Sep 5 14:10 exe -> /usr/bin/shellinaboxd
dr-x------ 2 root root 0 Sep 5 14:10 fd
dr-x------ 2 root root 0 Sep 5 14:11 fdinfo
-rw-r--r-- 1 root root 0 Sep 5 14:11 gid_map
-r-------- 1 root root 0 Sep 5 14:11 io
-r--r--r-- 1 root root 0 Sep 5 14:11 limits
-rw-r--r-- 1 root root 0 Sep 5 14:11 loginuid
dr-x------ 2 root root 0 Sep 5 14:11 map_files
-r--r--r-- 1 root root 0 Sep 5 14:11 maps
-rw------- 1 root root 0 Sep 5 14:11 mem
-r--r--r-- 1 root root 0 Sep 5 14:10 mountinfo
-r--r--r-- 1 root root 0 Sep 5 14:11 mounts
-r-------- 1 root root 0 Sep 5 14:11 mountstats
dr-xr-xr-x 5 nobody nogroup 0 Sep 5 14:11 net
dr-x--x--x 2 root root 0 Sep 5 14:10 ns
-r--r--r-- 1 root root 0 Sep 5 14:11 numa_maps
-rw-r--r-- 1 root root 0 Sep 5 14:11 oom_adj
-r--r--r-- 1 root root 0 Sep 5 14:11 oom_score
-rw-r--r-- 1 root root 0 Sep 5 14:10 oom_score_adj
-r-------- 1 root root 0 Sep 5 14:11 pagemap
-r-------- 1 root root 0 Sep 5 14:11 personality
-rw-r--r-- 1 root root 0 Sep 5 14:11 projid_map
lrwxrwxrwx 1 root root 0 Sep 5 14:11 root -> /
-rw-r--r-- 1 root root 0 Sep 5 14:11 sched
-r--r--r-- 1 root root 0 Sep 5 14:11 schedstat
-r--r--r-- 1 root root 0 Sep 5 14:11 sessionid
-rw-r--r-- 1 root root 0 Sep 5 14:11 setgroups
-r--r--r-- 1 root root 0 Sep 5 14:11 smaps
-r-------- 1 root root 0 Sep 5 14:11 stack
-r--r--r-- 1 root root 0 Sep 5 14:10 stat
-r--r--r-- 1 root root 0 Sep 5 14:11 statm
-r--r--r-- 1 root root 0 Sep 5 14:10 status
-r-------- 1 root root 0 Sep 5 14:11 syscall
dr-xr-xr-x 3 nobody nogroup 0 Sep 5 14:11 task
-r--r--r-- 1 root root 0 Sep 5 14:11 timers
-rw-r--r-- 1 root root 0 Sep 5 14:10 uid_map
-r--r--r-- 1 root root 0 Sep 5 14:11 wchan
ldh@ldh55:~$
ldh@ldh55:~$ ll /usr/bin/shellinaboxd
ls: cannot access '/usr/bin/shellinaboxd': No such file or directory
ldh@ldh55:~$
感谢@Amadan和@pitseeker，我检查了父进程的pstree，发现奇怪的进程可能是dockinabox进程，它在docker容器中，因为我也运行了shellinabox docker容器。
ldh@ldh55:~$ pstree -p 5675
docker-containe(5675)─┬─shellinaboxd(5693)───shellinaboxd(5758)
├─{docker-containe}(5676)
├─{docker-containe}(5677)
├─{docker-containe}(5678)
├─{docker-containe}(5679)
├─{docker-containe}(5680)
├─{docker-containe}(5681)
├─{docker-containe}(5682)
├─{docker-containe}(5683)
└─{docker-containe}(5757)
ldh@ldh55:~$ ps -ef|grep 5675
root 5675 15288 0 14:10 ? 00:00:00 docker-containerd-shim a865ae1d7398f23f8c3e484bce9817522b57a5f68d37a6756e812c93e72e4d1c /var/run/docker/libcontainerd/a865ae1d7398f23f8c3e484bce9817522b57a5f68d37a6756e812c93e72e4d1c docker-runc
nobody 5693 5675 0 14:10 ? 00:00:00 shellinaboxd -t -s /:LOGIN -s /python:shell:shell:HOME:/usr/bin/python -s /ipython:shell:shell:HOME:/usr/bin/ipython -s /python3:shell:shell:HOME:/usr/bin/python3 -s /ipython3:shell:shell:HOME:/usr/bin/ipython3 -s /cling:shell:shell:HOME:/usr/local/bin/cling --static-file=styles.css:/usr/local/share/shellinabox/shellinabox.css --user-css=Tomorrow Light:+/usr/local/share/shellinabox/theme-tomorrow-light.css,Tomorrow Dark:-/usr/local/share/shellinabox/theme-tomorrow-dark.css
ldh 104903 90695 0 15:11 pts/22 00:00:00 grep --color=auto 5675
ldh@ldh55:~$
ldh@ldh55:~$ docker ps|grep shellinabox
a865ae1d7398 9d6d77a31ef3 "shellinaboxd -t -..." 5 months ago Up About an hour 0.0.0.0:5200->4200/tcp shellinaboxshell_shellinabox-shell_1
ldh@ldh55:~$
ldh@ldh55:~$ docker stop a865ae1d7398
a865ae1d7398
ldh@ldh55:~$
ldh@ldh55:~$ ps -ef|grep shellinabox
ldh 115468 90695 0 15:17 pts/22 00:00:00 grep --color=auto shellinabox
ldh@ldh55:~$
ldh@ldh55:~$