Strange Log

[eng.waleed]

hi
my server has hang yesterday , and when I check the logs of apache I see this lines repeat
many time 
sh: /cd: No such file or directory
sh: /uptime: No such file or directory
sh: /uptime: No such file or directory
sh: /uptime: No such file or directory
sh: /uptime: No such file or directory
sh: /uptime: No such file or directory
sh: /uptime: No such file or directory
sh: /uptime: No such file or directory
sh: /uptime: No such file or directory
sh: /uptime: No such file or directory
sh: /uptime: No such file or directory
sh: /uptime: No such file or directory
sh: /uptime: No such file or directory
sh: /uptime: No such file or directory
sh: /uptime: No such file or directory
sh: /uptime: No such file or directory
sh: /uptime: No such file or directory
what it is mean ,who try to run /uptime script?
please help me