open ssh 的问题！

ansys

我的机器总是遇到这样的攻击，每次还都down机，谁给点建议！\r\n\r\nDec 25 13:43:54 www sshd[13417]: [ID 800047 auth.error] error: Could not get shadow information for NOUSER\r\nDec 25 13:43:54 www sshd[13419]: [ID 800047 auth.error] error: Could not get shadow information for NOUSER\r\nDec 25 13:43:55 www sshd[13421]: [ID 800047 auth.error] error: Could not get shadow information for NOUSER\r\nDec 25 13:43:55 www sshd[13423]: [ID 800047 auth.error] error: Could not get shadow information for NOUSER\r\nDec 25 13:43:55 www sshd[13425]: [ID 800047 auth.error] error: Could not get shadow information for NOUSER\r\nDec 25 13:43:56 www sshd[13427]: [ID 800047 auth.error] error: Could not get shadow information for NOUSER\r\nDec 25 13:43:56 www sshd[13429]: [ID 800047 auth.error] error: Could not get shadow information for NOUSER\r\nDec 25 13:43:56 www sshd[13431]: [ID 800047 auth.error] error: Could not get shadow information for NOUSER\r\nDec 25 13:43:56 www sshd[13433]: [ID 800047 auth.error] error: Could not get shadow information for NOUSER\r\nDec 25 13:43:57 www sshd[13435]: [ID 800047 auth.error] error: Could not get shadow information for NOUSER\r\nDec 25 13:43:57 www sshd[13437]: [ID 800047 auth.error] error: Could not get shadow information for NOUSER\r\nDec 25 13:43:58 www sshd[13441]: [ID 800047 auth.error] error: Could not get shadow information for NOUSER\r\nDec 25 13:43:58 www sshd[13443]: [ID 800047 auth.error] error: Could not get shadow information for NOUSER\r\nDec 25 13:43:59 www sshd[13445]: [ID 800047 auth.error] error: Could not get shadow information for NOUSER