Trojan.MSIL.Agent.ko_7945ce9aab

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

Process activity

The Trojan creates the following process(es):

303.exe:1840
Reader_sl.exe:1064
wuauclt.exe:344
jusched.exe:1056
%original file name%.exe:1480

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

303.exe:1192

File activity

The process 303.exe:1192 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\MSASCui.exe (601 bytes)
%System%\drivers\etc\hosts (120 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\errorchecker.txt (8 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\stcheck.txt (8 bytes)

The Trojan deletes the following file(s):

%Documents and Settings%\%current user%\Cookies\Current_User@ssl.bing[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@money.ca.msn[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@abmr[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@msnportal.112.2o7[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@kaspersky[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@www.msn[2].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@aaa[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@twitter[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@auto.search.msn[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@microsoft[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@c.msn[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@rambler[2].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@c.bing[2].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@kaspersky.122.2o7[2].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@c.ca.msn[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@atdmt[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@doubleclick[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@adnxs[2].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@hm.baidu[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@adgear[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@c.atdmt[2].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@insurance[2].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@bing[2].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@msn[2].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@yandex[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\index.dat (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@www.bing[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@tns-counter[1].txt (0 bytes)
%Documents and Settings%\%current user%\Cookies\Current_User@scorecardresearch[2].txt (0 bytes)

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

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

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

The process %original file name%.exe:1480 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\303.exe (129 bytes)

Registry activity

The process 303.exe:1840 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "42 D5 28 75 C6 03 B2 6F A6 D5 18 80 8E 64 BB 22"

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

The process 303.exe:1192 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "5E 66 A4 CF F5 3E CE 3A D8 76 DC 14 8F 56 A2 AE"

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

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

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

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd75-744b-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\{b98117e8-75ca-11e2-81b2-000c293708fb}]
"BaseClass" = "Drive"

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

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]
"Windows Defender" = "%Documents and Settings%\%current user%\Local Settings\Temp\MSASCui.exe"

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

The Trojan 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"

The process %original file name%.exe:1480 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "86 67 E7 67 AC EB E8 2A 8A 35 01 78 34 BB 93 13"

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

Network activity (URLs)

No activity has been detected.

HOSTS file anomalies

The Trojan modifies "%System%\drivers\etc\hosts" file which is used to translate DNS entries to IP addresses. The modified file is 120 bytes in size. The following strings are added to the hosts file listed below:

127.0.0.1	74.53.201.162
127.0.0.1	66.66.132.220.30
127.0.0.1	66.35.241.92
127.0.0.1	94.23.199.60

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'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):

   303.exe:1840
   wuauclt.exe:344
   %original file name%.exe:1480

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

   %Documents and Settings%\%current user%\Local Settings\Temp\MSASCui.exe (601 bytes)
   %System%\drivers\etc\hosts (120 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\errorchecker.txt (8 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\stcheck.txt (8 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)
   %Documents and Settings%\%current user%\Local Settings\Temp\303.exe (129 bytes)

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

   [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   "Windows Defender" = "%Documents and Settings%\%current user%\Local Settings\Temp\MSASCui.exe"

5. Restore the original content of the HOSTS file (%System%\drivers\etc\hosts): 127.0.0.1 localhost
   
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