DHL spam campaign leads to MokesLoader Trojan Downloader (Jan 06, 2012)

By

SonicWALL UTM Research team observed a increase in spam campaigns employing DHL package delivery schemes. The emails pretending to be from DHL informs the user of a package being sent to their address and that the relevant tracking number is in the attachment. The zipped attachment in the email is a newer variant of the MokesLoader Trojan downloader.

Email subjects used in this spam campaign include:

  • DHL Delivery refuse
  • DHL Error package delivery
  • DHL shipment status No***
  • Error in the delivery address
  • Error in the delivery address No*******
  • Error package delivery
  • Get your parcel No***
  • Shipment Status No***
  • Track your parcel No******
  • Track your shipment No****

The body of the email is as shown below:

 ---------------------------------------------------------------------  Dear customer.     Your package has been sent to your address.    Please find a post label attached which contains a track number of    your package.     Thank you for your attention.    DHL Global Services.  ---------------------------------------------------------------------	 

The following file with a misleading icon is present in the zip attachment:

screenshot

It performs the following activities when executed:

  • It creates the following files:
    • %appdata%csrss.exe (Copy of itself) [Detected as GAV: “MokesLoader.MS (Trojan)]
    • %appdata%MicrosoftProtectqbfbv.xx
    • %appdata%MicrosoftProtectrpphtrt.nv
  • It reports new infection to a remote server using a uniquely generated login id:
    • GET /aaa/index.php?cmd=getload&login={removed}&sel=sp3ya&ver=5.1&bits=0&file=1&run=ok
  • It creates the following registry entries to ensure infection on reboot:
    • HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionPoliciesExplorerRun Clients “%appdata%csrss.exe”
    • HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun mcoyr “rundll32 %appdata%MICROS~1Protectrpphtrt.nv, itgn”
    • HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun imfblgk “rundll32 %appdata%MICROS~1Protectqbfbv.xx, namn”
  • It creates a TCP backdoor on the infected machine
    screenshot
  • It reports backdoor port to remote server:
    • GET /aaa/index.php?cmd=getsocks&login={removed}&port=2592 HTTP/1.1
  • The following commands were used to communicate with remote server
    • getgrab
    • getproxy
    • getload
    • getsocks
  • It receives instructions from remote server and downloads additional malware.

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

  • GAV: MokesLoader.MS (Trojan)
  • GAV: MokesLoader.MK (Trojan)
  • GAV: MokesLoader.LS (Trojan)
  • GAV: MokesLoader.LH (Trojan)
  • GAV: Dofoil.L#email (Trojan)

screenshot

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.