Worm.Win32.Ainslot.VB_3979f50746

Dynamic Analysis

Process activity

The Worm creates the following process(es):

3979f50746c26eca08d30a264db8fda0.exe:448
reg.exe:1536
reg.exe:440
reg.exe:544
reg.exe:896
tmp1.tmp.exe:1260
tmp1.tmp.exe:1288

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

wininit.exe:496

File activity

The process 3979f50746c26eca08d30a264db8fda0.exe:448 makes changes in a file system.

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

%Documents and Settings%\%current user%\Local Settings\Temp\temp_lXHqZHvCkq\wininit.exe (7547 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\tmp1.tmp.exe (9606 bytes)

The Worm deletes the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\tmp1.tmp (0 bytes)

The process wininit.exe:496 makes changes in a file system.

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

%Documents and Settings%\%current user%\Application Data\skype.exe (3860 bytes)
%Documents and Settings%\%current user%\Application Data\winlogon (32 bytes)

Registry activity

The process 3979f50746c26eca08d30a264db8fda0.exe:448 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "9F C2 53 49 6E CF 00 5A A6 85 CE F2 CB 41 D9 5F"

[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"

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

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

[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\ShellNoRoam\MUICache\%Documents and Settings%\%current user%\Local Settings\Temp]
"tmp1.tmp.exe" = "EpicBot Setup"

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

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

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

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

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

The Worm modifies IE settings for security zones to map all local web-nodes with no dots which do not refer to any zone to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"UNCAsIntranet" = "1"

The Worm modifies IE settings for security zones to map all urls to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"IntranetName" = "1"

The Worm modifies IE settings for security zones to map all web-nodes that bypassing proxy to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"ProxyBypass" = "1"

The process reg.exe:1536 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "94 65 5E 01 7C 6A 9E 69 58 5D C8 3A 05 6F 3D 91"

Adds a rule to the firewall Windows which allows any network activity:

[HKLM\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List\%Documents and Settings%\%current user%\Local Settings\Temp\temp_lXHqZHvCkq]
"wininit.exe" = "%Documents and Settings%\%current user%\Local Settings\Temp\temp_lXHqZHvCkq\wininit.exe:*:Enabled:Windows Messanger"

The process reg.exe:440 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "25 B3 20 40 E0 B4 86 63 05 84 19 89 2D 7B 8F 45"

Adds a rule to the firewall Windows which allows any network activity:

[HKLM\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List\%Documents and Settings%\%current user%\Application Data]
"skype.exe" = "%Documents and Settings%\%current user%\Application Data\skype.exe:*:Enabled:Windows Messanger"

The process reg.exe:544 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "4C E6 F1 9A 85 81 C1 CF 6E 86 FD E7 1A 0B 14 FB"

[HKLM\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile]
"DoNotAllowExceptions" = "0"

The process reg.exe:896 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "D4 68 1B A9 A8 D6 F5 01 81 81 E7 A9 00 C9 E2 23"

[HKLM\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile]
"DoNotAllowExceptions" = "0"

The process wininit.exe:496 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "4D DD A6 1F AE 12 F2 6A 19 1D 07 E4 4C 92 82 0D"

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

[HKCU\Software\VB and VBA Program Settings\INSTALL\DATE]
"9XZOAZER8Z" = "July 9, 2013"

[HKCU\Software\VB and VBA Program Settings\SrvID\ID]
"9XZOAZER8Z" = "network"

The process tmp1.tmp.exe:1260 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "39 6C D5 B6 E6 F8 11 F1 A6 F1 C5 19 D8 AE 3A 4B"

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

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

The Worm adds the reference to itself to be executed when a user logs on:

[HKCU\Software\Microsoft\Windows NT\CurrentVersion\Winlogon]
"Shell" = "%Documents and Settings%\%current user%\Local Settings\Temp\tmp1.tmp.exe;%WinDir%\Explorer.exe"

The process tmp1.tmp.exe:1288 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "1B 60 7E 6B B0 2B D8 21 3A 21 A7 29 3E 77 8F 14"

[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"

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

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

[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\Shell Folders]
"AppData" = "%Documents and Settings%\%current user%\Application Data"

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

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

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

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

The Worm modifies IE settings for security zones to map all local web-nodes with no dots which do not refer to any zone to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"UNCAsIntranet" = "1"

The Worm modifies IE settings for security zones to map all urls to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"IntranetName" = "1"

The Worm modifies IE settings for security zones to map all web-nodes that bypassing proxy to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"ProxyBypass" = "1"

Network activity (URLs)

URL: hxxp://dl-balancer.x.dropbox.com/FileToDownload.exe Country: United States
URL: minecrafthere.zapto.org IP: 124.148.251.250
URL: dl.dropbox.com IP: 54.235.160.111

Rootkit activity

No anomalies have been detected.

Propagation

A worm spreads via removable drives. It writes its executable and creates "autorun.inf" scripts on all removable drives. The autorun script will execute the Worm'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):

   3979f50746c26eca08d30a264db8fda0.exe:448
   reg.exe:1536
   reg.exe:440
   reg.exe:544
   reg.exe:896
   tmp1.tmp.exe:1260
   tmp1.tmp.exe:1288

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

   %Documents and Settings%\%current user%\Local Settings\Temp\temp_lXHqZHvCkq\wininit.exe (7547 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\tmp1.tmp.exe (9606 bytes)
   %Documents and Settings%\%current user%\Application Data\skype.exe (3860 bytes)
   %Documents and Settings%\%current user%\Application Data\winlogon (32 bytes)

4. Remove the references to the Worm by modifying the following registry value(s) (How to Work with System Registry):

   [HKCU\Software\Microsoft\Windows NT\CurrentVersion\Winlogon]
   "Shell" = "%Documents and Settings%\%current user%\Local Settings\Temp\tmp1.tmp.exe;%WinDir%\Explorer.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