BKDR_COINMINE.FJ
Backdoor:Win32/Fynloski.A (Microsoft); Trojan.Gen (Symantec); Trojan.MSIL.Crypt.abed (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Inject.AEEX (AVG)
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This backdoor 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
6,512,640 bytes
EXE
Yes
24 Jul 2013
Arrival Details
This backdoor 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 backdoor drops the following copies of itself into the affected system:
- %User Profile%\Application Data\gigapp.exe
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
It creates the following folders:
- %User Profile%\Application Data\dclogs
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
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
btqc = "%User Profile%\Application Data\gigapp.exe"
Other System Modifications
This backdoor modifies the following file(s):
- %Application Data%\GDIPFONTCACHEV1.DAT
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)
It deletes the following files:
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.1740.108468
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.1740.108515
- %User Profile%\v2.0.50727.42\security.config.cch.1740.109890
(Note: %Windows% is the Windows folder, which is usually C:\Windows.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
It adds the following registry keys:
HKEY_CURRENT_USER\Software\DC3_FEXEC
It adds the following registry entries:
HKEY_CURRENT_USER\Software\DC3_FEXEC
7/7/2013 at 1:01:50 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
GDIPlus
FontCachePath = "%Application Data%"
(Note: The default value data of the said registry entry is %User Profile%\Local Settings\Application Data.)
Dropping Routine
This backdoor drops the following files:
- %User Temp%\QTBITCOINTRADER.EXE
- gigapp.exe:ZONE.identifier
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
This report is generated via an automated analysis system.
SOLUTION
9.300
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
Step 3
Delete this registry key
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
- DC3_FEXEC
Step 4
Delete this registry value
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
- btqc = "%User Profile%\Application Data\gigapp.exe"
- In HKEY_CURRENT_USER\Software\DC3_FEXEC
- 7/7/2013 at 1:01:50 PM = "{1c6961c0-f82d-11e0-a6bd-806d6172696f-1756172240}"
Step 5
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Software\Microsoft\GDIPlus
- From: FontCachePath = "%Application Data%"
To: FontCachePath = ""%User Profile%\Local Settings\Application Data""
- From: FontCachePath = "%Application Data%"
Step 6
Search and delete these components
- %User Temp%\QTBITCOINTRADER.EXE
- gigapp.exe:ZONE.identifier
Step 7
Search and delete this folder
- %User Profile%\Application Data\dclogs
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_COINMINE.FJ. 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 9
Restore deleted/modified files and/or registry entries from backup
*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- %Application Data%\GDIPFONTCACHEV1.DAT
Step 10
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.1740.108468
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.1740.108515
- %User Profile%\v2.0.50727.42\security.config.cch.1740.109890
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