$ grep "invalid user" /var/log/secure.log
Jan 11 09:30:31 silverbox sshd[6475]: input_userauth_request: invalid user staff
Jan 11 09:30:34 silverbox sshd[6479]: input_userauth_request: invalid user sales
Jan 11 09:30:39 silverbox sshd[6481]: input_userauth_request: invalid user recruit
Jan 11 09:30:42 silverbox sshd[6483]: input_userauth_request: invalid user alias
Jan 11 09:30:44 silverbox sshd[6485]: input_userauth_request: invalid user office
Jan 11 09:30:47 silverbox sshd[6492]: input_userauth_request: invalid user samba
Jan 11 09:30:50 silverbox sshd[6494]: input_userauth_request: invalid user tomcat
Jan 11 09:30:52 silverbox sshd[6496]: input_userauth_request: invalid user webadmin
Jan 11 09:30:55 silverbox sshd[6498]: input_userauth_request: invalid user spam
Jan 11 09:30:58 silverbox sshd[6500]: input_userauth_request: invalid user virus
Jan 11 09:31:01 silverbox sshd[6502]: input_userauth_request: invalid user cyrus
Jan 11 09:31:04 silverbox sshd[6504]: input_userauth_request: invalid user oracle
Jan 11 09:31:07 silverbox sshd[6508]: input_userauth_request: invalid user michael
Jan 11 09:31:13 silverbox sshd[6512]: input_userauth_request: invalid user test
Jan 11 09:31:15 silverbox sshd[6514]: input_userauth_request: invalid user webmaster
Jan 11 09:31:18 silverbox sshd[6516]: input_userauth_request: invalid user postmaster
Jan 11 09:31:23 silverbox sshd[6520]: input_userauth_request: invalid user postgres
Jan 11 09:31:26 silverbox sshd[6522]: input_userauth_request: invalid user paul
Jan 11 09:31:31 silverbox sshd[6526]: input_userauth_request: invalid user guest
Jan 11 09:31:34 silverbox sshd[6528]: input_userauth_request: invalid user admin
Jan 11 09:31:37 silverbox sshd[6532]: input_userauth_request: invalid user linux
Jan 11 09:31:41 silverbox sshd[6534]: input_userauth_request: invalid user user
Jan 11 09:31:44 silverbox sshd[6536]: input_userauth_request: invalid user david
Jan 11 09:31:47 silverbox sshd[6538]: input_userauth_request: invalid user web
Jan 11 09:31:50 silverbox sshd[6540]: input_userauth_request: invalid user apache
Jan 11 09:31:53 silverbox sshd[6542]: input_userauth_request: invalid user pgsql
Jan 11 09:31:58 silverbox sshd[6546]: input_userauth_request: invalid user info
Jan 11 09:32:01 silverbox sshd[6548]: input_userauth_request: invalid user tony
Jan 11 09:32:04 silverbox sshd[6550]: input_userauth_request: invalid user core
Jan 11 09:32:08 silverbox sshd[6554]: input_userauth_request: invalid user newsletter
Jan 11 09:32:11 silverbox sshd[6556]: input_userauth_request: invalid user named
Jan 11 09:32:14 silverbox sshd[6558]: input_userauth_request: invalid user visitor
Jan 11 09:32:18 silverbox sshd[6560]: input_userauth_request: invalid user ftpuser
Jan 11 09:32:20 silverbox sshd[6562]: input_userauth_request: invalid user username
Jan 11 09:32:22 silverbox sshd[6565]: input_userauth_request: invalid user administrator
Jan 11 09:32:26 silverbox sshd[6567]: input_userauth_request: invalid user library
Jan 11 09:32:29 silverbox sshd[6569]: input_userauth_request: invalid user test
Jan 11 09:32:37 silverbox sshd[6577]: input_userauth_request: invalid user admin
Jan 11 09:32:39 silverbox sshd[6579]: input_userauth_request: invalid user guest
Jan 11 09:32:42 silverbox sshd[6581]: input_userauth_request: invalid user master
Jan 11 09:32:57 silverbox sshd[6593]: input_userauth_request: invalid user admin
Jan 11 09:33:01 silverbox sshd[6595]: input_userauth_request: invalid user admin
Jan 11 09:33:03 silverbox sshd[6597]: input_userauth_request: invalid user admin
Jan 11 09:33:06 silverbox sshd[6599]: input_userauth_request: invalid user admin
Jan 11 09:33:15 silverbox sshd[6607]: input_userauth_request: invalid user test
Jan 11 09:33:18 silverbox sshd[6609]: input_userauth_request: invalid user test
Jan 11 09:33:21 silverbox sshd[6611]: input_userauth_request: invalid user webmaster
Jan 11 09:33:23 silverbox sshd[6613]: input_userauth_request: invalid user username
Jan 11 09:33:26 silverbox sshd[6615]: input_userauth_request: invalid user user
Jan 11 09:33:34 silverbox sshd[6619]: input_userauth_request: invalid user admin
Jan 11 09:33:39 silverbox sshd[6621]: input_userauth_request: invalid user test
Jan 11 09:33:52 silverbox sshd[6631]: input_userauth_request: invalid user danny
Jan 11 09:33:56 silverbox sshd[6633]: input_userauth_request: invalid user alex
Jan 11 09:33:58 silverbox sshd[6635]: input_userauth_request: invalid user brett
Jan 11 09:34:01 silverbox sshd[6637]: input_userauth_request: invalid user mike
Jan 11 09:34:05 silverbox sshd[6639]: input_userauth_request: invalid user alan
Jan 11 09:34:08 silverbox sshd[6641]: input_userauth_request: invalid user data
Jan 11 09:34:12 silverbox sshd[6643]: input_userauth_request: invalid user www-data
Jan 11 09:34:15 silverbox sshd[6647]: input_userauth_request: invalid user http
Jan 11 09:34:17 silverbox sshd[6649]: input_userauth_request: invalid user httpd
Jan 11 09:34:20 silverbox sshd[6651]: input_userauth_request: invalid user pop
Jan 11 09:34:29 silverbox sshd[6657]: input_userauth_request: invalid user backup
Jan 11 09:34:32 silverbox sshd[6659]: input_userauth_request: invalid user info
Jan 11 09:34:35 silverbox sshd[6661]: input_userauth_request: invalid user shop
Jan 11 09:34:38 silverbox sshd[6663]: input_userauth_request: invalid user sales
Jan 11 09:34:44 silverbox sshd[6665]: input_userauth_request: invalid user web
Jan 11 09:34:51 silverbox sshd[6671]: input_userauth_request: invalid user wwwrun
Jan 11 09:34:55 silverbox sshd[6674]: input_userauth_request: invalid user adam
Jan 11 09:34:58 silverbox sshd[6676]: input_userauth_request: invalid user stephen
Jan 11 09:35:01 silverbox sshd[6678]: input_userauth_request: invalid user richard
Jan 11 09:35:04 silverbox sshd[6680]: input_userauth_request: invalid user george
Jan 11 09:35:11 silverbox sshd[6682]: input_userauth_request: invalid user john
Jan 11 09:35:15 silverbox sshd[6684]: input_userauth_request: invalid user news
Jan 11 09:35:18 silverbox sshd[6688]: input_userauth_request: invalid user angel
Jan 11 09:35:22 silverbox sshd[6690]: input_userauth_request: invalid user games
Jan 11 09:35:25 silverbox sshd[6692]: input_userauth_request: invalid user pgsql
Jan 11 09:35:28 silverbox sshd[6697]: input_userauth_request: invalid user mail
Jan 11 09:35:31 silverbox sshd[6702]: input_userauth_request: invalid user adm
Jan 11 09:35:34 silverbox sshd[6707]: input_userauth_request: invalid user ident
Jan 11 09:35:38 silverbox sshd[6712]: input_userauth_request: invalid user webpop
Jan 11 09:35:40 silverbox sshd[6714]: input_userauth_request: invalid user susan
Jan 11 09:35:43 silverbox sshd[6716]: input_userauth_request: invalid user sunny
Jan 11 09:35:46 silverbox sshd[6718]: input_userauth_request: invalid user steven
Jan 11 09:35:50 silverbox sshd[6723]: input_userauth_request: invalid user ssh
Jan 11 09:35:53 silverbox sshd[6725]: input_userauth_request: invalid user search
Jan 11 09:35:59 silverbox sshd[6727]: input_userauth_request: invalid user sara
Jan 11 09:36:05 silverbox sshd[6730]: input_userauth_request: invalid user robert
Jan 11 09:36:08 silverbox sshd[6733]: input_userauth_request: invalid user richard
Jan 11 09:36:11 silverbox sshd[6735]: input_userauth_request: invalid user party
Jan 11 09:36:15 silverbox sshd[6737]: input_userauth_request: invalid user amanda
Jan 11 09:36:18 silverbox sshd[6739]: input_userauth_request: invalid user rpm
Jan 11 09:36:21 silverbox sshd[6743]: input_userauth_request: invalid user operator
Jan 11 09:36:24 silverbox sshd[6746]: input_userauth_request: invalid user sgi
Jan 11 09:36:29 silverbox sshd[6750]: input_userauth_request: invalid user users
Jan 11 09:36:32 silverbox sshd[6752]: input_userauth_request: invalid user admins
Jan 11 09:36:35 silverbox sshd[6754]: input_userauth_request: invalid user admins
Jan 11 09:36:37 silverbox sshd[6756]: input_userauth_request: invalid user bin
Jan 11 09:36:45 silverbox sshd[6762]: input_userauth_request: invalid user sync
Jan 11 09:36:48 silverbox sshd[6764]: input_userauth_request: invalid user shutdown
Jan 11 09:36:50 silverbox sshd[6766]: input_userauth_request: invalid user halt
Jan 11 09:36:53 silverbox sshd[6770]: input_userauth_request: invalid user uucp
Jan 11 09:36:56 silverbox sshd[6772]: input_userauth_request: invalid user smmsp
Jan 11 09:36:59 silverbox sshd[6774]: input_userauth_request: invalid user dean
Jan 11 09:37:19 silverbox sshd[6788]: input_userauth_request: invalid user agent
Jan 11 09:37:46 silverbox sshd[6810]: input_userauth_request: invalid user telnetd
Jan 11 09:37:48 silverbox sshd[6812]: input_userauth_request: invalid user identd
Jan 11 09:37:52 silverbox sshd[6814]: input_userauth_request: invalid user gnats
Jan 11 09:37:55 silverbox sshd[6818]: input_userauth_request: invalid user jeff
Jan 11 09:37:58 silverbox sshd[6820]: input_userauth_request: invalid user irc
Jan 11 09:38:01 silverbox sshd[6822]: input_userauth_request: invalid user list
Jan 11 09:38:04 silverbox sshd[6824]: input_userauth_request: invalid user eleve
Jan 11 09:38:07 silverbox sshd[6826]: input_userauth_request: invalid user proxy
Jan 11 09:38:09 silverbox sshd[6828]: input_userauth_request: invalid user sys
Jan 11 09:38:12 silverbox sshd[6830]: input_userauth_request: invalid user zzz
Jan 11 09:38:15 silverbox sshd[6832]: input_userauth_request: invalid user frank
Jan 11 09:38:18 silverbox sshd[6834]: input_userauth_request: invalid user dan
Jan 11 09:38:21 silverbox sshd[6836]: input_userauth_request: invalid user james
Jan 11 09:38:24 silverbox sshd[6838]: input_userauth_request: invalid user snort
Jan 11 09:38:27 silverbox sshd[6842]: input_userauth_request: invalid user radiomail
Jan 11 09:38:30 silverbox sshd[6844]: input_userauth_request: invalid user harrypotter
Jan 11 09:38:33 silverbox sshd[6846]: input_userauth_request: invalid user divine
Jan 11 09:38:36 silverbox sshd[6848]: input_userauth_request: invalid user popa3d
Jan 11 09:38:38 silverbox sshd[6850]: input_userauth_request: invalid user aptproxy
Jan 11 09:38:41 silverbox sshd[6852]: input_userauth_request: invalid user desktop
Jan 11 09:38:43 silverbox sshd[6854]: input_userauth_request: invalid user workshop
Jan 11 09:38:46 silverbox sshd[6856]: input_userauth_request: invalid user mailnull
Jan 11 09:38:49 silverbox sshd[6859]: input_userauth_request: invalid user nfsnobody
Jan 11 09:38:51 silverbox sshd[6864]: input_userauth_request: invalid user rpcuser
Jan 11 11:18:17 silverbox sshd[7020]: input_userauth_request: invalid user sales
Jan 11 11:18:23 silverbox sshd[7024]: input_userauth_request: invalid user recruit
Jan 11 11:18:26 silverbox sshd[7026]: input_userauth_request: invalid user alias
Jan 11 11:18:29 silverbox sshd[7028]: input_userauth_request: invalid user office
Jan 11 11:18:32 silverbox sshd[7030]: input_userauth_request: invalid user samba
Jan 11 11:18:37 silverbox sshd[7032]: input_userauth_request: invalid user tomcat
Jan 11 11:18:41 silverbox sshd[7034]: input_userauth_request: invalid user webadmin
Jan 11 11:18:45 silverbox sshd[7036]: input_userauth_request: invalid user spam
Jan 11 11:18:48 silverbox sshd[7038]: input_userauth_request: invalid user virus
Jan 11 11:18:53 silverbox sshd[7042]: input_userauth_request: invalid user cyrus
Jan 11 11:18:57 silverbox sshd[7044]: input_userauth_request: invalid user oracle
Jan 11 11:18:59 silverbox sshd[7046]: input_userauth_request: invalid user michael
Jan 11 11:19:06 silverbox sshd[7050]: input_userauth_request: invalid user test
Jan 11 11:19:10 silverbox sshd[7052]: input_userauth_request: invalid user webmaster
Jan 11 11:19:18 silverbox sshd[7054]: input_userauth_request: invalid user postmaster
Jan 11 11:19:29 silverbox sshd[7060]: input_userauth_request: invalid user postgres