PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size: 515,072 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 26 Oct 2015

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Trojan creates the following folders:

  • %Program Files%\aaveglqktfnogcfntqly

(Note: %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
dkmbbsbugtwjlyo = "%Program Files%\aaveglqktfnogcfntqly\drhqmwi.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\Software\AXSPH

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
ax0 = "23.109.38.158"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
ax3 = "http://{BLOCKED}.38.158/cadastro/clientes/index.php"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
ax4 = "linea[arq].servepics.com"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
ax5 = "127.0.0.1"

HKEY_LOCAL_MACHINE
ev = "345344234"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
lx = "345341234"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
pr = "283234"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
au = "283234"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
ax0 = "284285280283282291280285290280283287290234"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
ax3 = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
ax4 = "342339344335331325331348347327280349335348352335346339333349280333345343234"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
ax1 = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
ax2 = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
axx = "dnfbyj"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
axh = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
vi = "345341234"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
cf1 = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
pr = "345341"

HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
vp = "325320266290280282327"

Dropping Routine

This Trojan drops the following files:

  • %System Root%\wefwwnt.tmp
  • %Program Files%\aaveglqktfnogcfntqly\gfmwn
  • %Program Files%\aaveglqktfnogcfntqly\dnfbyj
  • %Program Files%\aaveglqktfnogcfntqly\drhqmwi
  • %Program Files%\aaveglqktfnogcfntqly\drhqmwi.exe
  • %Program Files%\aaveglqktfnogcfntqly\iexplore.exe

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}.38.158/system/cab/arqb.cab
  • http://{BLOCKED}.38.158/system/cab/arqa.cab
  • http://{BLOCKED}.38.158/system/pdf/st1.pdf
  • {BLOCKED}0.1

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.750

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Restart in Safe Mode

[ Learn More ]

Step 3

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\Software
    • AXSPH

Step 4

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • dkmbbsbugtwjlyo = "%Program Files%\aaveglqktfnogcfntqly\drhqmwi.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • ax0 = "23.109.38.158"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • ax3 = "http://{BLOCKED}.38.158/cadastro/clientes/index.php"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • ax4 = "linea[arq].servepics.com"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • ax5 = "127.0.0.1"
  • In HKEY_LOCAL_MACHINE
    • ev = "345344234"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • lx = "345341234"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • pr = "283234"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • au = "283234"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • ax0 = "284285280283282291280285290280283287290234"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • ax3 = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • ax4 = "342339344335331325331348347327280349335348352335346339333349280333345343234"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • ax1 = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • ax2 = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • axx = "dnfbyj"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • axh = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • vi = "345341234"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • cf1 = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • pr = "345341"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\AXSPH
    • vp = "325320266290280282327"

Step 5

Search and delete these components

[ Learn More ]
There may be some components that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %System Root%\wefwwnt.tmp
  • %Program Files%\aaveglqktfnogcfntqly\gfmwn
  • %Program Files%\aaveglqktfnogcfntqly\dnfbyj
  • %Program Files%\aaveglqktfnogcfntqly\drhqmwi
  • %Program Files%\aaveglqktfnogcfntqly\drhqmwi.exe
  • %Program Files%\aaveglqktfnogcfntqly\iexplore.exe

Step 6

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %Program Files%\aaveglqktfnogcfntqly

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_BROBANLAW.J. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


Did this description help? Tell us how we did.