TrojanDownloader.Win32.Zlob.absq_680f27396e

Dynamic Analysis

Payload

Behaviour	Description
WormAutorun	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-Downloader's file once a user opens a drive's folder in Windows Explorer.
IRCBot	A bot can communicate with command and control servers via IRC channel.

Process activity

The Trojan-Downloader creates the following process(es):

%original file name%.exe:1648
Reader_sl.exe:1064
wuauclt.exe:344
jusched.exe:1056

The Trojan-Downloader injects its code into the following process(es):No processes have been created.

File activity

The process %original file name%.exe:1648 makes changes in the file system.

The Trojan-Downloader creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)
%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\3ZILFCAH\desktop.ini (67 bytes)
%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\K5670HEX\desktop.ini (67 bytes)
%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\ANW7E3GB\desktop.ini (67 bytes)
%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\CPQNC967\desktop.ini (67 bytes)
%System%\drivers\winlogon.exe (601 bytes)

The process wuauclt.exe:344 makes changes in the file system.

The Trojan-Downloader creates and/or writes to the following file(s):

%WinDir%\SoftwareDistribution\DataStore\Logs\edb.chk (100 bytes)
%WinDir%\SoftwareDistribution\DataStore\Logs\edb.log (3576 bytes)
%WinDir%\SoftwareDistribution\DataStore\DataStore.edb (100 bytes)

The Trojan-Downloader deletes the following file(s):

%WinDir%\SoftwareDistribution\DataStore\Logs\tmp.edb (0 bytes)

The process jusched.exe:1056 makes changes in the file system.

The Trojan-Downloader creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\jusched.log (347 bytes)

Registry activity

The process %original file name%.exe:1648 makes changes in the system registry.

The Trojan-Downloader creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "67 FF 27 7D A5 3D F8 09 28 2E C1 E1 C5 A9 F0 3F"

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

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache2"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache1"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3]
"CacheLimit" = "65452"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1]
"CacheLimit" = "65452"

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

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths]
"Directory" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path4]
"CacheLimit" = "65452"
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache4"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache3"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths]
"Paths" = "4"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Shell Extensions]
"j" = "c:\%original file name%.exe"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cache" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2]
"CacheLimit" = "65452"

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

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
"winlogon.exe" = "%System%\drivers\winlogon.exe"

The process Reader_sl.exe:1064 makes changes in the system registry.

The Trojan-Downloader creates and/or sets the following values in system registry:

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

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

[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"

Network activity (URLs)

URL	IP
www.topgameland.com	Unresolvable
mail.fucuzzy.com	Unresolvable
mail.tiktikz.com	Unresolvable
www.genesisstore.sk	Unresolvable

HOSTS file anomalies

No changes have been detected.

Rootkit activity

No anomalies have been detected.

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-Downloader's file once a user opens a drive's folder in Windows Explorer.

Removals

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. Terminate malicious process(es) (How to End a Process With the Task Manager):

   %original file name%.exe:1648
   wuauclt.exe:344
   

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

   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\3ZILFCAH\desktop.ini (67 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\K5670HEX\desktop.ini (67 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\ANW7E3GB\desktop.ini (67 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\CPQNC967\desktop.ini (67 bytes)
   %System%\drivers\winlogon.exe (601 bytes)
   %WinDir%\SoftwareDistribution\DataStore\Logs\edb.chk (100 bytes)
   %WinDir%\SoftwareDistribution\DataStore\Logs\edb.log (3576 bytes)
   %WinDir%\SoftwareDistribution\DataStore\DataStore.edb (100 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\jusched.log (347 bytes)

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

   [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   "winlogon.exe" = "%System%\drivers\winlogon.exe"

5. Clean the Temporary Internet Files folder, which may contain infected files (How to clean Temporary Internet Files folder).
   
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.

Static Analysis

Network Activity

Map

Strings from Dumps