eFax spam campaign delivers info stealer Trojan (Oct 26, 2012)


Dell SonicWALL UTM Research team discovered a new info stealer Trojan in the wild that steals account information from FTP and Email configuration files. The Trojan also drops a variant of the Zbot Trojan on the system.

The Trojan arrives in the form of an email purporting to be a fax message delivered by eFax Corporate. The user is encouraged to download and execute the attachment to view the fax:

Upon infection the Trojan performs the following DNS queries:

  • dechotheband.gr
  • barisdogalurunler.com
  • alpertarimurunleri.com
  • oneglobalexchange.com
  • rumanas.org
  • www.10130138.wavelearn.de
  • visiosofttechnologies.com
  • sgisolution.com.br
  • plusloinart.be
  • marengoit.pl
  • www.google.com

The Trojan adds the following files to the filesystem:

  • %USERPROFILE%Local SettingsTemp215229.exe [Detected as GAV: Zbot.AAN_62 (Trojan)]
  • %USERPROFILE%Local SettingsTemp220286.exe [Detected as GAV: Zbot.AAN_62 (Trojan)]
  • %USERPROFILE%Local SettingsTemp224803.exe [Detected as GAV: Zbot.AAN_62 (Trojan)]
  • %USERPROFILE%Local SettingsTemp227637.exe [Detected as GAV: Zbot.AAN_62 (Trojan)]
  • %USERPROFILE%Local SettingsTemp230491.exe [Detected as GAV: Zbot.AAN_62 (Trojan)]
  • %USERPROFILE%Local SettingsTemp231913.exe [Detected as GAV: Zbot.AAN_62 (Trojan)]
  • %USERPROFILE%Local SettingsTemp233065.exe [Detected as GAV: Zbot.AAN_62 (Trojan)]
  • %USERPROFILE%Local SettingsTemp249648.exe [Detected as GAV: Zbot.AAN_62 (Trojan)]
  • %USERPROFILE%Local SettingsTemp252302.exe [Detected as GAV: Zbot.AAN_62 (Trojan)]
  • %APPDATA%Ettohxiud.exe [Detected as GAV: Zbot.EQLN_2 (Trojan)]
  • %USERPROFILE%Local SettingsTempabcd.bat

abcd.bat contains the following data. This is used to clean up parts of the infection process:

      del %1
      if exist %1 goto
      del %0

The Trojan adds the following key to the Windows registry to enable startup after reboot:

  • HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRun {C05E9BBE-21ED-AD41-CB90-673CEB12442E} “%APPDATA%Ettohxiud.exe”

The Trojan downloads and runs the following files [All detected as GAV: Zbot.AAN_62 (Trojan)] from various remote webservers:

The following encrypted communication was observed between the Trojan and a remote C&C webserver:

The unencrypted form of the above “CRYPTED” data that is sent is as follows. It contains sensitive system information::

The Trojan was observed iterating through the Program Files directory looking for FTP and Email configuration files. It steals credentials from the following FTP and Email softwares if present.

      BulletProof FTP
      Smart FTP
      Turbo FTP
      Sota's FTP
      FTP Navigator
      FTP Commander
      Cute FTP
      Core FTP
      Ultra FXP
      FTP Explorer
      Classic FTP
      Wise FTP
      Leech FTP
      Go FTP
      The Bat!

The Trojan contains the following common word password list:

SonicWALL Gateway AntiVirus provides protection against this threat via the following signatures:

  • GAV: Androm.EFX
  • GAV: Tepfer.AIUQ
  • GAV: Zbot.EQLN_2
  • GAV: Zbot.AAN_62
Security News
The SonicWall Capture Labs Threat Research Team gathers, analyzes and vets cross-vector threat information from the SonicWall Capture Threat network, consisting of global devices and resources, including more than 1 million security sensors in nearly 200 countries and territories. The research team identifies, analyzes, and mitigates critical vulnerabilities and malware daily through in-depth research, which drives protection for all SonicWall customers. In addition to safeguarding networks globally, the research team supports the larger threat intelligence community by releasing weekly deep technical analyses of the most critical threats to small businesses, providing critical knowledge that defenders need to protect their networks.