{"id":43,"date":"2007-11-04T00:43:38","date_gmt":"2007-11-03T16:43:38","guid":{"rendered":"http:\/\/www.sysadmindayph.com\/blog\/cover-your-tracks-after-hacking-a-unix-box\/"},"modified":"2012-06-16T22:13:32","modified_gmt":"2012-06-16T14:13:32","slug":"cover-your-tracks-after-hacking-a-unix-box","status":"publish","type":"post","link":"http:\/\/www.sysadmindayph.com\/blog\/cover-your-tracks-after-hacking-a-unix-box\/","title":{"rendered":"Cover Your Tracks After Hacking A UNIX Box"},"content":{"rendered":"

In the Monitoring User Login<\/a> post, the commands and files that are related in tracking user activities are discussed.<\/p>\n

Here are some ways of covering your fingerprints on a server using the files that monitors user logins<\/a>.<\/p>\n

We want to erase any trace that will show that we were inside the box. In doing so we’ll just:<\/p>\n

cat \/dev\/null > <file><\/p><\/blockquote>\n

Lastlog file<\/strong><\/p>\n

Clear out the last log file if you’re using an existing user from the box. Lastlogin file shows when and where a particular user last login from.<\/p>\n

login: razile
\nPassword:<\/code><\/span><\/p>\n

Last login: Fri Oct 21 21:50:02 2007 from 210.2.9.1<\/strong>
\nSun Microsystems Inc. SunOS 5.9 Generic May 2002
\nrazile@unix-box %<\/p><\/blockquote>\n

Erase that if you don’t want the admin see where you last login from (IP, hostname, time etc)<\/p>\n

cat \/dev\/null > \/var\/adm\/lastlogin<\/p><\/blockquote>\n

After clearing the lastlog file, comparing the first login and the second one:<\/p>\n

(first login)<\/p>\n

Last login: Thu Nov\u00a0 1 21:33:41 2007 from 210.23.109.1
\nSun Microsystems Inc.\u00a0\u00a0 SunOS 5.9\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Generic May 2002
\nuser@server-><\/p><\/blockquote>\n

(after deletion)<\/p>\n

\u00a0Sun Microsystems Inc.\u00a0\u00a0 SunOS 5.9\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Generic May 2002
\nbash: unalias: `e’: not an alias
\nuser@server-><\/p><\/blockquote>\n

wtmpx\/tmpx files<\/strong><\/p>\n

If you want to check those users who logged in to a Unix box, type in ‘last’<\/p>\n

UnixBox# last | more
\nroot\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 pts\/21\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 101.221.224.61\u00a0\u00a0\u00a0 Sat Nov\u00a0 3 11:38\u00a0\u00a0 still logged in
\nsitescp\u00a0\u00a0 pts\/20\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 19.168.128.132\u00a0 Sat Nov\u00a0 3 07:00\u00a0\u00a0 still logged in
\nroot\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 pts\/23\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 101.221.224.51\u00a0\u00a0\u00a0 Sat Nov\u00a0 3 05:05\u00a0\u00a0 still logged in
\nroot\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 pts\/22\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 101.221.224.51\u00a0\u00a0\u00a0 Sat Nov\u00a0 3 05:05\u00a0\u00a0 still logged in
\npaladel\u00a0\u00a0\u00a0 pts\/22\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 14.122.4.99\u00a0\u00a0\u00a0\u00a0 Fri Nov\u00a0 2 14:33 – 15:32\u00a0 (00:59)
\nboy1\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0 pts\/26\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 14.122.4.67\u00a0\u00a0\u00a0\u00a0 Fri Nov\u00a0 2 13:22 – 14:50\u00a0 (01:28)
\nboy2\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0 pts\/26\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 14.122.4.67\u00a0\u00a0\u00a0\u00a0 Fri Nov\u00a0 2 13:20 – 13:22\u00a0 (00:02)<\/p><\/blockquote>\n

You’ll see the user who was logged in, the terminal used, the IP where he came from the date or duration of his activity in the server.<\/p>\n

That is a lot of information, so in covering up your track, delete or zero out the files that stores these information<\/p>\n

cat \/dev\/null > \/var\/adm\/wtmpx
\ncat \/dev\/null > \/var\/adm\/tmpx<\/p><\/blockquote>\n

After doing so, you’ll get this when doing ‘last’<\/p>\n

# cat \/dev\/null > \/var\/adm\/wtmpx
\n# last | more<\/p>\n

wtmp begins Sun Nov\u00a0 4 00:41
\n#<\/p><\/blockquote>\n

You could also zero out the \/var\/adm\/messages if you’re really paranoid.<\/p>\n

Of course doing these is like shouting and telling the whole universe that you were there.<\/p>\n

These are just a few to cover you track… Do you have any additions? Or any tips in covering the intrusion without knowing that you were there?<\/p>\n","protected":false},"excerpt":{"rendered":"

In the Monitoring User Login post, the commands and files that are related in tracking user activities are discussed. Here are some ways of covering your fingerprints on a server using the files that monitors …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,8],"tags":[],"class_list":["post-43","post","type-post","status-publish","format-standard","hentry","category-solaris","category-tips"],"_links":{"self":[{"href":"http:\/\/www.sysadmindayph.com\/blog\/wp-json\/wp\/v2\/posts\/43","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.sysadmindayph.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.sysadmindayph.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.sysadmindayph.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.sysadmindayph.com\/blog\/wp-json\/wp\/v2\/comments?post=43"}],"version-history":[{"count":3,"href":"http:\/\/www.sysadmindayph.com\/blog\/wp-json\/wp\/v2\/posts\/43\/revisions"}],"predecessor-version":[{"id":347,"href":"http:\/\/www.sysadmindayph.com\/blog\/wp-json\/wp\/v2\/posts\/43\/revisions\/347"}],"wp:attachment":[{"href":"http:\/\/www.sysadmindayph.com\/blog\/wp-json\/wp\/v2\/media?parent=43"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.sysadmindayph.com\/blog\/wp-json\/wp\/v2\/categories?post=43"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.sysadmindayph.com\/blog\/wp-json\/wp\/v2\/tags?post=43"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}