This malware is the filelessly-installed backdoor malware discovered on early August 2017. Users whose systems are affected by this particular malware may find the security of their systems compromised.
This Backdoor may be downloaded by other malware/grayware from remote sites.
It deletes registry entries, causing some applications and programs to not function properly.
It does not have any propagation routine.
It executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.
Arrival Details
This Backdoor may be downloaded by the following malware/grayware from remote sites:
It may be downloaded from the following remote sites:
- https://{BLOCKED}ndo.ru/favicon
Installation
This Backdoor adds the following processes:
- WerFault.exe (Windows Vista and above) / ctfmon.exe (Windows XP and below)
- msiexec.exe
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- Global\Mutex_4e1c16d7187ac191a832a41f7192645425dad5c792b76ed1dd7071926289ac66
It injects codes into the following process(es):
- created WerFault.exe/ctfmon.exe
- created msiexec.exe
Autostart Technique
This Backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{UID} = "%System%\WindowsPowerShell\v1.0\powershell.exe -WindowStyle hidden -NoLogo -NonInteractive -ep bypass -nop iex ([Text.Encoding]::ASCII.GetString([Convert]::FromBase64String((gp 'HKCU:\Software\Classes\{random character}').{random character})));"
Other System Modifications
This Backdoor adds the following registry entries:
HKEY_CURRENT_USER\Software\Classes\
{random characters}
{random characters} = {base 64 encoded powershell command}
HKEY_CURRENT_USER\Software\Classes\
{random characters}
{UID} = {encrypted binary data}
HKEY_CURRENT_USER\Console\%SystemRoot%\
_system32_WIndowsPowerShell_v1.0_powershell.exe
WindowPosition = 4294905760
HKEY_CURRENT_USER\Console\%SystemRoot%\
_system32_WIndowsPowerShell_v1.0_powershell.exe
ScreenBufferSize = 65616
HKEY_CURRENT_USER\Console\%SystemRoot%\
_system32_WIndowsPowerShell_v1.0_powershell.exe
WindowSize = 65616
It deletes the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
taskmgr.exe
Debugger = "taskmgr.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{UID} = {where the data has the following strings}:
- "powershell"
- "-windowstyle hidden"
- "[Text.Encoding]::ASCII.GetString([Convert]::FromBase64String"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
COM+ = {current value}
Propagation
This Backdoor does not have any propagation routine.
Backdoor Routine
This Backdoor executes the following commands from a remote malicious user:
- Start a Process
- Download a file directed by C&C server, save it as %User Temp%\KB{8 random numbers}.exe and execute it
- Copy %System%\cdosys.dll to %User Temp%\cdo{random number}.dll and load it
- Uninstall itself
(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
It connects to the following websites to send and receive information:
- http://{Random Generated Domain}/nonc.so
- http://{BLOCKED}an.ru/q.php
- http://{BLOCKED}ano.ru/q.php
Process Termination
This Backdoor terminates the following processes if found running in the affected system's memory:
Information Theft
This Backdoor gathers the following data:
- Root Volume Serial Number
- Operating System Version
- Local IP Address
- Administrator privileges
Other Details
This Backdoor connects to the following URL(s) to check for an Internet connection:
It does the following:
- It uses the following powershell command to decrypt and execute the base64 encoded powershell command in the registry:
"%System%\WindowsPowerShell\v1.0\powershell.exe -WindowStyle hidden -NoLogo -NonInteractive -ep bypass -nop iex ([Text.Encoding]::ASCII.GetString([Convert]::FromBase64String((gp 'HKCU:\Software\Classes\{random characters}').{random character})));" - It checks for the following requirements to proceed with its routine:
- No existing "Global\Mutex_4e1c16d7187ac191a832a41f7192645425dad5c792b76ed1dd7071926289ac66" mutex
- No existing "C:\Python27" folder
- Presence of "%System%\WindowsPowerShell\v1.0\powershell.exe"
- It connects to the following Network Time Protocol (NTP) servers:
- africa.pool.ntp.org
- oceania.pool.ntp.org
- asia.pool.ntp.org
- south-america.pool.ntp.org
- north-america.pool.ntp.org
- europe.pool.ntp.org
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
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
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 3
Restart in Safe Mode
[ Learn More ]
[ back ]
To restart in Safe Mode:
• For Windows 2000 users
- Restart your computer.
- Press F8 when you see the Starting Windows bar at the bottom of the screen.
- Choose the Safe Mode option from the Windows Advanced Options menu then press Enter.
• For Windows XP users
- Restart your computer.
- Press F8 after the Power-On Self Test (POST) routine is done. If the Windows Advanced Options menu does not appear, try restarting then pressing F8 several times when the POST screen appears.
- Choose the Safe Mode option from the Windows Advanced Options menu then press Enter.
• For Windows Server 2003 users
- Restart your computer.
- Press F8 after Windows starts up. If the Windows Advanced Options menu does not appear, try restarting again and pressing F8 several times afterward.
- On the Windows Advanced Option menu, use the arrow keys to select Safe Mode then press Enter.
• For Windows Vista, Windows 7, and Windows Server 2008 users
- Restart your computer.
- Press F8 after the Power-On Self Test (POST) routine is done. If the Advanced Boot Options menu does not appear, try restarting and then pressing F8 several times after the POST screen is displayed.
- On the Advanced Boot Options menu, use the arrow keys to select the Safe Mode option, and then press Enter.
• For Windows 8, Windows 8.1, and Windows Server 2012 users
- Access the Charms bar by moving your mouse pointer to the upper right corner of the screen.
- Move your mouse pointer down and click Settings>Change your PC Settings.
- In the left panel, click General.
- In the right panel, scroll down to the bottom to find the Advanced startup section, then click the Restart now button and wait for the system to restart.
- In the Advanced Startup menu, click Troubleshoot>Advanced Options>Startup Settings>Restart and wait for the system to restart.
- In the Startup Settings menu, press 4 to enable safe mode.
Step 4
Delete this registry value
[ Learn More ]
[ back ]
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- {UID} = "%System%\WindowsPowerShell\v1.0\powershell.exe -WindowStyle hidden -NoLogo -NonInteractive -ep bypass -nop iex ([Text.Encoding]::ASCII.GetString([Convert]::FromBase64String((gp 'HKCU:\Software\Classes\{random character}').{random character})));"
- In HKEY_CURRENT_USER\Software\Classes\{random characters}
- {random characters} = {base 64 encoded powershell command}
- In HKEY_CURRENT_USER\Software\Classes\{random characters}
- {UID} = {encrypted binary data}
- In HKEY_CURRENT_USER\Console\%SystemRoot%\_system32_WIndowsPowerShell_v1.0_powershell.exe
- WindowPosition = 4294905760
- In HKEY_CURRENT_USER\Console\%SystemRoot%\_system32_WIndowsPowerShell_v1.0_powershell.exe
- In HKEY_CURRENT_USER\Console\%SystemRoot%\_system32_WIndowsPowerShell_v1.0_powershell.exe
To delete the registry value this malware created:
- Open Registry Editor. To do this:
» For Windows 2000, Windows XP, and Windows Server 2003 users, click Start>Run, type regedit in the text box provided, and then press Enter.
» For Windows Vista, Windows 7, and Windows Server 2008 users, click the Start button, type regedit in the Search input field then press Enter.
» For Windows 8, Windows 8.1, and Windows Server 2012 users, right-click on the lower left corner of the screen, click Run, type regedit in the text box provided, and then press Enter. - In the left panel of the Registry Editor window, double-click the following:
HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>Run - In the right panel, locate and delete the entry:
{UID} = "%System%\WindowsPowerShell\v1.0\powershell.exe -WindowStyle hidden -NoLogo -NonInteractive -ep bypass -nop iex ([Text.Encoding]::ASCII.GetString([Convert]::FromBase64String((gp 'HKCU:\Software\Classes\{random character}').{random character})));" - In the left panel of the Registry Editor window, double-click the following:
HKEY_CURRENT_USER>Software>Classes>{random characters} - In the right panel, locate and delete the entry:
{random characters} = {base 64 encoded powershell command} - Again In the right panel, locate and delete the entry:
{UID} = {encrypted binary data} - In the left panel of the Registry Editor window, double-click the following:
HKEY_CURRENT_USER>Console>%SystemRoot%>_system32_WIndowsPowerShell_v1.0_powershell.exe - In the right panel, locate and delete the entry:
WindowPosition = 4294905760 - Again In the right panel, locate and delete the entry:
ScreenBufferSize = 65616 - Again In the right panel, locate and delete the entry:
WindowSize = 65616 - Close Registry Editor.
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_ANDROM.ETIN. 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.
Step 6
Scan your computer with your Trend Micro product to delete files detected as BKDR_ANDROM.ETIN. 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.