approximately 21 minutes worth log file recording attacks on a typical Linux system...

 entries changed from log file - IPs are actual 
 note the user names attempted
 note the ports attempted (a firewall prevents access to worms or logins to various ports)
 these attempts were the ones SEEN because a service was enabled
 the attempts made on other services or parts were rejected and not logged - there were/are many
 good passwords are the best defense on a Linux server
 these IP's typically originate in China, SE Asia, Russia and other nefarious locations - look 'em up.
 linux systems are highly desirable - offer a platform to attack Microsoft systems



Jun 10 21:04:25 Linux log[99907]: Received disconnect from 121.18.238.106 port 59043:11:  [reported]
Jun 10 21:04:25 Linux log[99907]: Disconnected from 121.18.238.106 port 59043 [reported]
Jun 10 21:08:42 Linux log[99911]: Received disconnect from 59.45.175.24 port 52026:11:  [reported]
Jun 10 21:08:42 Linux log[99911]: Disconnected from 59.45.175.24 port 52026 [reported]
Jun 10 21:10:23 Linux log[99916]: Invalid user 0 from 31.207.47.36
Jun 10 21:10:23 Linux log[99916]: Connection closed by 31.207.47.36 port 56857 [reported]
Jun 10 21:10:25 Linux log[99918]: Invalid user 0000 from 31.207.47.36
Jun 10 21:10:25 Linux log[99918]: Connection closed by 31.207.47.36 port 51008 [reported]
Jun 10 21:10:26 Linux log[99920]: Invalid user 010101 from 31.207.47.36
Jun 10 21:10:26 Linux log[99920]: Connection closed by 31.207.47.36 port 42227 [reported]
Jun 10 21:10:28 Linux log[99922]: Invalid user 1111 from 31.207.47.36
Jun 10 21:10:28 Linux log[99922]: Connection closed by 31.207.47.36 port 55904 [reported]
Jun 10 21:10:29 Linux log[99924]: Connection closed by 31.207.47.36 port 40174 [reported]
Jun 10 21:10:31 Linux log[99926]: Invalid user 1234 from 31.207.47.36
Jun 10 21:10:31 Linux log[99926]: Connection closed by 31.207.47.36 port 53628 [reported]
Jun 10 21:10:32 Linux log[99928]: Invalid user admin from 31.207.47.36
Jun 10 21:10:33 Linux log[99928]: Connection closed by 31.207.47.36 port 60473 [reported]
Jun 10 21:10:34 Linux log[99930]: Invalid user admin from 31.207.47.36
Jun 10 21:10:35 Linux log[99930]: Connection closed by 31.207.47.36 port 33799 [reported]
Jun 10 21:10:37 Linux log[99932]: Invalid user admin from 31.207.47.36
Jun 10 21:10:38 Linux log[99932]: Connection closed by 31.207.47.36 port 35850 [reported]
Jun 10 21:10:39 Linux log[99934]: Invalid user admin from 31.207.47.36
Jun 10 21:10:40 Linux log[99934]: Connection closed by 31.207.47.36 port 53321 [reported]
Jun 10 21:10:41 Linux log[99936]: Invalid user admin from 31.207.47.36
Jun 10 21:10:42 Linux log[99936]: Connection closed by 31.207.47.36 port 45411 [reported]
Jun 10 21:10:43 Linux log[99938]: Invalid user admin from 31.207.47.36
Jun 10 21:10:44 Linux log[99938]: Connection closed by 31.207.47.36 port 38977 [reported]
Jun 10 21:10:45 Linux log[99940]: Invalid user api from 31.207.47.36
Jun 10 21:10:45 Linux log[99940]: Connection closed by 31.207.47.36 port 57200 [reported]
Jun 10 21:10:47 Linux log[99942]: Invalid user dbadmin from 31.207.47.36
Jun 10 21:10:47 Linux log[99942]: Connection closed by 31.207.47.36 port 48005 [reported]
Jun 10 21:10:48 Linux log[99944]: Invalid user default from 31.207.47.36
Jun 10 21:10:48 Linux log[99944]: Connection closed by 31.207.47.36 port 60071 [reported]
Jun 10 21:10:50 Linux log[99946]: Invalid user default from 31.207.47.36
Jun 10 21:10:50 Linux log[99946]: Connection closed by 31.207.47.36 port 44960 [reported]
Jun 10 21:10:52 Linux log[99948]: Connection closed by 31.207.47.36 port 55218 [reported]
Jun 10 21:10:53 Linux log[99950]: Invalid user ftpuser from 31.207.47.36
Jun 10 21:10:53 Linux log[99950]: Connection closed by 31.207.47.36 port 39587 [reported]
Jun 10 21:10:55 Linux log[99952]: Invalid user git from 31.207.47.36
Jun 10 21:10:55 Linux log[99952]: Connection closed by 31.207.47.36 port 59255 [reported]
Jun 10 21:10:56 Linux log[99954]: Connection closed by 31.207.47.36 port 50177 [reported]
Jun 10 21:10:58 Linux log[99956]: Invalid user gpadmin from 31.207.47.36
Jun 10 21:10:58 Linux log[99956]: Connection closed by 31.207.47.36 port 34301 [reported]
Jun 10 21:10:59 Linux log[99958]: Invalid user guest from 31.207.47.36
Jun 10 21:10:59 Linux log[99958]: Connection closed by 31.207.47.36 port 45271 [reported]
Jun 10 21:11:01 Linux log[99960]: Invalid user monitor from 31.207.47.36
Jun 10 21:11:01 Linux log[99960]: Connection closed by 31.207.47.36 port 59893 [reported]
Jun 10 21:11:02 Linux log[99962]: Invalid user mysql from 31.207.47.36
Jun 10 21:11:03 Linux log[99962]: Connection closed by 31.207.47.36 port 38964 [reported]
Jun 10 21:11:04 Linux log[99964]: Invalid user mysql from 31.207.47.36
Jun 10 21:11:04 Linux log[99964]: Connection closed by 31.207.47.36 port 60969 [reported]
Jun 10 21:11:05 Linux log[99966]: Invalid user operator from 31.207.47.36
Jun 10 21:11:06 Linux log[99966]: Connection closed by 31.207.47.36 port 47563 [reported]
Jun 10 21:11:07 Linux log[99968]: Connection closed by 31.207.47.36 port 37919 [reported]
Jun 10 21:11:09 Linux log[99970]: Invalid user pi from 31.207.47.36
Jun 10 21:11:09 Linux log[99970]: Connection closed by 31.207.47.36 port 50194 [reported]
Jun 10 21:11:11 Linux log[99972]: Connection closed by 31.207.47.36 port 36497 [reported]
Jun 10 21:11:13 Linux log[99974]: Connection closed by 31.207.47.36 port 46164 [reported]
Jun 10 21:11:15 Linux log[99976]: Connection closed by 31.207.47.36 port 42290 [reported]
Jun 10 21:11:16 Linux log[99978]: Invalid user service from 31.207.47.36
Jun 10 21:11:16 Linux log[99978]: Connection closed by 31.207.47.36 port 35143 [reported]
Jun 10 21:11:17 Linux log[99980]: Connection closed by 31.207.47.36 port 51012 [reported]
Jun 10 21:11:19 Linux log[99982]: Invalid user support from 31.207.47.36
Jun 10 21:11:19 Linux log[99982]: Connection closed by 31.207.47.36 port 33433 [reported]
Jun 10 21:11:20 Linux log[99984]: Invalid user sysadmin from 31.207.47.36
Jun 10 21:11:21 Linux log[99984]: Connection closed by 31.207.47.36 port 49248 [reported]
Jun 10 21:11:22 Linux log[99986]: Invalid user telecomadmin from 31.207.47.36
Jun 10 21:11:22 Linux log[99986]: Connection closed by 31.207.47.36 port 59105 [reported]
Jun 10 21:11:23 Linux log[99988]: Invalid user telnet from 31.207.47.36
Jun 10 21:11:24 Linux log[99988]: Connection closed by 31.207.47.36 port 50718 [reported]
Jun 10 21:11:25 Linux log[99990]: Invalid user test from 31.207.47.36
Jun 10 21:11:25 Linux log[99990]: Connection closed by 31.207.47.36 port 39973 [reported]
Jun 10 21:11:27 Linux log[99992]: Connection closed by 31.207.47.36 port 60751 [reported]
Jun 10 21:11:28 Linux log[99994]: Invalid user ubnt from 31.207.47.36
Jun 10 21:11:28 Linux log[99994]: Connection closed by 31.207.47.36 port 43644 [reported]
Jun 10 21:11:29 Linux log[99996]: Invalid user user from 31.207.47.36
Jun 10 21:11:30 Linux log[99996]: Connection closed by 31.207.47.36 port 55696 [reported]
Jun 10 21:11:31 Linux log[99998]: Invalid user user1 from 31.207.47.36
Jun 10 21:11:32 Linux log[99998]: Connection closed by 31.207.47.36 port 43366 [reported]
Jun 10 21:11:33 Linux log[99900]: Connection closed by 31.207.47.36 port 54217 [reported]
Jun 10 21:12:05 Linux log[99902]: error: maximum authentication attempts exceeded for root from 119.119.128.27 port 8701 ssh2 [reported]
Jun 10 21:16:48 Linux log[99968]: Invalid user user from 124.195.222.19
Jun 10 21:16:49 Linux log[99968]: error: maximum authentication attempts exceeded for invalid user user from 124.195.222.19 port 36999 ssh2 [reported]
Jun 10 21:21:41 Linux log[99981]: Received disconnect from 212.237.23.27 port 56464:11: Bye Bye [reported]
Jun 10 21:21:41 Linux log[99981]: Disconnected from 212.237.23.27 port 56464 [reported]