MD5: f3a8a95ff24f0ad90376af7d45eabb77
SHA1: aa9f922877c1bb1d3204b0d60a56e2b805411531
SHA256: 06eff6e70ae3d85343189d60dff84f12d783402aaf9284b65bc7bde505d97c39
SSDeep: 3072:NvdFHFSdaWvWo4Hsi5ehNV4o2JJ9wToBYK6tQyGg2LYGLPg:xFlWvOHxi0oc9wToz6GyGg2LYa
Size: 194048 bytes
File type: EXE
Platform: WIN32
Entropy: Packed
PEID: UPolyXv05_v6, MicrosoftVisualC, MicrosoftVisualCv50v60MFC, MicrosoftVisualC50, Armadillov171
Company: no certificate found
Created at: 2011-09-06 02:16:45
Analyzed on: WindowsXP SP3 32-bit

Summary:

Trojan-Dropper. Trojan program, intended for stealth installation of other malware into user's system.

Payload

Process activity

The Trojan creates the following process(es):

imapi.exe:824
%original file name%.exe:1708
%original file name%.exe:1280
%original file name%.exe:1196
drwtsn32.exe:1324
Ctkmko.exe:676
Ctkmko.exe:564
Ctkmko.exe:1356

The Trojan injects its code into the following process(es):

mscorsvw.exe:1920
rundll32.exe:492

Mutexes

The following mutexes were created/opened:
No objects were found.

File activity

The process imapi.exe:824 makes changes in the file system.
The Trojan creates and/or writes to the following file(s):

%WinDir%\Temp\fwjtntz6.TMP (146970 bytes)

The process %original file name%.exe:1708 makes changes in the file system.
The Trojan creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Application Data\Ctkmko.exe (673 bytes)

The process %original file name%.exe:1196 makes changes in the file system.
The Trojan creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Application Data\Microsoft\Crypto\RSA\S-1-5-21-1844237615-1960408961-1801674531-1003\c5b88721db08c824db69d0bbc702beb8_75ed9567-aa58-4c8e-a8ea-3cad7c47ab03 (44 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\EtfDtg1eKDiK6AhE6Jl.tmp (3 bytes)

The process drwtsn32.exe:1324 makes changes in the file system.
The Trojan creates and/or writes to the following file(s):

%Documents and Settings%\All Users\Application Data\Microsoft\Dr Watson\user.dmp (183728 bytes)
%Documents and Settings%\All Users\Application Data\Microsoft\Dr Watson\drwtsn32.log (389686 bytes)

The process Ctkmko.exe:676 makes changes in the file system.
The Trojan creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\EtfDtg1eKDiK6AhE6Jl.tmp (3 bytes)

Registry activity

The process imapi.exe:824 makes changes in the system registry.
The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "D6 14 BC 8D B6 6A 65 E9 D9 0C D0 68 A4 F9 C5 70"

[HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Tracing\Microsoft\Imapi]
"ControlFlags" = "1"
"Active" = "1"

[HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Tracing\Microsoft\Imapi\ImapiSvc]
"BitNames" = " ImapiDebugError ImapiDebugWarning ImapiDebugTrace ImapiDebugInfo ImapiDebugX ImapiDebugSort"

[HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Tracing\Microsoft\Imapi]
"LogSessionName" = "stdout"

[HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Tracing\Microsoft\Imapi\ImapiSvc]
"Guid" = "8107d8e9-e323-49f5-bba2-abc35c243dca"

The process rundll32.exe:492 makes changes in the system registry.
The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "03 C1 D4 C3 D7 9E 62 54 DA 86 29 4B B8 A9 70 C6"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd73-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd72-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{b98117e8-75ca-11e2-81b2-000c293708fb}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd75-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Personal" = "%Documents and Settings%\%current user%\My Documents"

The process %original file name%.exe:1708 makes changes in the system registry.
The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "7C 53 6E D6 63 15 75 3F 8E 86 E5 85 4B D9 FD AD"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"

To automatically run itself each time Windows is booted, the Trojan adds the following link to its file to the system registry autorun key:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
"Ctkmko" = "%Documents and Settings%\%current user%\Application Data\Ctkmko.exe"

The process %original file name%.exe:1280 makes changes in the system registry.
The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "C6 7C B3 4B 2F 04 74 03 8C F9 6A A0 7B B5 9F A1"

The process %original file name%.exe:1196 makes changes in the system registry.
The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "2B 99 17 57 45 97 8C 72 02 C7 80 9F 90 84 4F F8"

The process drwtsn32.exe:1324 makes changes in the system registry.
The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "A8 92 99 76 C6 F1 53 C9 EA 33 7D 9D A3 1F 40 17"

[HKLM\SOFTWARE\Microsoft\DrWatson]
"NumberOfCrashes" = "1"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Common AppData" = "%Documents and Settings%\All Users\Application Data"

The process Ctkmko.exe:676 makes changes in the system registry.
The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "12 75 9C 44 87 BC BB 3F DE F3 44 D6 1B 46 F1 8B"

The process Ctkmko.exe:564 makes changes in the system registry.
The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "49 6E CC 62 DE A4 90 81 56 2C C9 BB EE BA E3 A6"

The process Ctkmko.exe:1356 makes changes in the system registry.
The Trojan creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "AD A4 05 29 62 59 95 ED A5 4C 24 5E 61 1F DF 45"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"

Dropped PE files

HOSTS file anomalies

No changes have been detected.

Rootkit activity

The Trojan installs the following user-mode hooks in WININET.dll:

HttpSendRequestW
InternetWriteFile
HttpSendRequestA

The Trojan installs the following user-mode hooks in ADVAPI32.dll:

RegCreateKeyExA
RegCreateKeyExW

The Trojan installs the following user-mode hooks in WS2_32.dll:

send
getaddrinfo

The Trojan installs the following user-mode hooks in kernel32.dll:

MoveFileA
CopyFileW
CopyFileA
MoveFileW
CreateFileW
CreateFileA

The Trojan installs the following user-mode hooks in ntdll.dll:

LdrLoadDll
NtResumeThread
NtQueryDirectoryFile
NtEnumerateValueKey

Propagation

A worm can spread via removable drives. It writes its executable and creates "autorun.inf" scripts on all removable drives. The autorun script will execute the Trojan's file once a user opens a drive's folder in Windows Explorer.
A program can register a device notification with the help of RegisterDeviceNotification. So it is notified when a USB device is plugged and then the worm copies itself to the USB device plugged into the affected computer.
A worm can spread its copies through the MSN Messanger.

VersionInfo

Company Name: Pink Image
Product Name: Pink Image
Product Version: 1, 0, 0, 1
Legal Copyright: Copyright (c) 2011
Legal Trademarks:
Original Filename: TStub.exe
Internal Name: Pink Image
File Version: 1, 0, 0, 1
File Description: Pink Image
Comments:
Language: English (United States)

PE Sections

Dropped from:

Downloaded by:

Similar by SSDeep:

Similar by Lavasoft Polymorphic Checker:

URLs

No activity has been detected.

IDS verdicts (Suricata alerts: Emerging Threats ET ruleset)

Traffic

Web Traffic was not found.

The Trojan connects to the servers at the folowing location(s):

Remove it with Ad-Aware

1. Click (here) to download and install Ad-Aware Free Antivirus.
2. Update the definition files.
3. Run a full scan of your computer.

Manual removal*

1. Scan a system with an anti-rootkit tool.
   
2. Terminate malicious process(es) (How to End a Process With the Task Manager):
   

   imapi.exe:824
   %original file name%.exe:1708
   %original file name%.exe:1280
   %original file name%.exe:1196
   drwtsn32.exe:1324
   Ctkmko.exe:676
   Ctkmko.exe:564
   Ctkmko.exe:1356
   

3. Delete the original Trojan file.
   
4. Delete or disinfect the following files created/modified by the Trojan:
   

   %WinDir%\Temp\fwjtntz6.TMP (146970 bytes)
   %Documents and Settings%\%current user%\Application Data\Ctkmko.exe (673 bytes)
   %Documents and Settings%\%current user%\Application Data\Microsoft\Crypto\RSA\S-1-5-21-1844237615-1960408961-1801674531-1003\c5b88721db08c824db69d0bbc702beb8_75ed9567-aa58-4c8e-a8ea-3cad7c47ab03 (44 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\EtfDtg1eKDiK6AhE6Jl.tmp (3 bytes)
   %Documents and Settings%\All Users\Application Data\Microsoft\Dr Watson\user.dmp (183728 bytes)
   %Documents and Settings%\All Users\Application Data\Microsoft\Dr Watson\drwtsn32.log (389686 bytes)
   

5. Delete the following value(s) in the autorun key (How to Work with System Registry):
   

   [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   "Ctkmko" = "%Documents and Settings%\%current user%\Application Data\Ctkmko.exe"

6. Find and delete all copies of the worm's file together with "autorun.inf" scripts on removable drives.
   
7. Reboot the computer.
   

*Manual removal may cause unexpected system behaviour and should be performed at your own risk.