加强安全:看清黑客怎样入侵linux

以下是引用片段：
　C:\ping www.XXX.com 
　　Pinging www.XXX.com[202.106.184.200] with 32 bytes of data: 
　　Reply from 202.106.184.200: bytes=32 time=541ms TTL=244 
　　Reply from 202.106.184.200: bytes=32 time=620ms TTL=244 
　　Reply from 202.106.184.200: bytes=32 time=651ms TTL=244 
　　Reply from 202.106.184.200: bytes=32 time=511ms TTL=244 
　　Ping statistics for 202.106.184.200: 
　　Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), 
　　Approximate round trip times in milli-seconds: 
　　Minimum = 511ms, Maximum = 651ms, Average = 580ms 
　　嘻嘻—不但连得上，速度还不错…… 
　　先telnet看看banner： 
      　　C:\>telnet www.XXX.com

以下是引用片段：
C:\>ftp www.XXX.com 
　　Connected to www.fbi.gov.tw. 
　　220 XXX-www FTP server (Version wu-2.6.1(1) Wed Aug 9 05:54:50 EDT 2000) ready. 
      　　User (www.XXX.com:(none)):

以下是引用片段：
　C:\>telnet xxx.xxx.xxx.xxx 
　　Red Hat Linux release 7.0 (Guinness) 
　　Kernel 2.2.16-22smp on an i686 
　　login: fetdog 
　　Password: 
      　　bash-2.04$

以下是引用片段：
　bash-2.04$nmap -sT -O www.XXX.com 
　　Starting nmap V. 2.54BETA7 ( www.insecure.org/nmap/ ) 
　　WARNING! The following files exist and are readable: /usr/local/sha 
　　-services and ./nmap-services. I am choosing /usr/local/share/nmap/ 
　　s for security reasons. set NMAPDIR=. to give priority to files in 
　　irectory 
　　Interesting ports on (www.XXX.com): 
　　(The 1520 ports scanned but not shown below are in state: closed) 
　　Port State Service 
　　25/tcp open smtp 
　　79/tcp open finger 
　　80/tcp open http 
　　111/tcp open sunrpc 
　　113/tcp open auth 
　　443/tcp open https 
　　513/tcp open login 
　　514/tcp open shell 
　　515/tcp open printer 
　　587/tcp open submission 
　　1024/tcp open kdm 
　　TCP Sequence Prediction: Class=random positive increments 
　　Difficulty=3247917 (Good luck!) 
　　Remote operating system guess: Linux 2.1.122 - 2.2.16 
      　　Nmap run completed -- 1 IP address (1 host up) scanned in 9 seconds