TROJ_FAM_000193a.TOMA

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It modifies files, disabling programs and applications from properly running.

Arrival Details

This Trojan 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 Trojan drops the following copies of itself into the affected system:

• %Program Files%\common files\system\ms1src.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)

Other System Modifications

This Trojan modifies the following files:

• %User Profile%\Application Data\Microsoft

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

It deletes the following files:

• %User Temp%\qdelwbi.tmp
• %System%\safesearch.exe
• %Program Files%\primesoft\safesearch\safesearch.exe
• %System%\_SafeSearch.dll
• %System%\SafeSearch.dll
• %Program Files%\common files\system\ms1src.exe:Zone.Identifier
• \ms1src_update.exe

(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.. %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.. %Program Files% is the default Program Files folder, usually C:\Program Files.)

It deletes the following folders:

• %Program Files%\primesoft\safesearch
• %Program Files%\primesoft

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)

It adds the following registry keys:

HKEY_CLASSES_ROOT\CLSID\{00000000-0000-0000-0000-000000000001}\
InprocServer32

HKEY_CURRENT_USER\Software\Program Data

HKEY_CURRENT_USER\Software\InfoSoft\
qsearch

HKEY_CURRENT_USER\Software\Program Info

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Program Data
SSET = "ECR#171A02951E83"

HKEY_CURRENT_USER\Software\InfoSoft\
qsearch
GetIDRetryCounter = "0"

HKEY_CURRENT_USER\Software\Program Info
ClientID = "{78aa8b3a-10e7-432b-a4a7-4f5624a8fac5}"

HKEY_CURRENT_USER\Software\InfoSoft\
qsearch
LastWNK = "4f9db344"

HKEY_CURRENT_USER\Software\InfoSoft\
qsearch
FlashID = "1227362"

HKEY_CURRENT_USER\Software\InfoSoft\
qsearch
DaytimeDocID = "-1"

HKEY_CURRENT_USER\Software\InfoSoft\
qsearch
DaytimeDocTime = "0"

HKEY_CURRENT_USER\Software\InfoSoft\
qsearch
GetInfoRetryCounter = "0"

It modifies the following registry entries:

HKEY_CURRENT_USER\SessionInformation
ProgramCount = "1"

(Note: The default value data of the said registry entry is 2.)

HKEY_CURRENT_USER\SessionInformation
ProgramCount = "0"

(Note: The default value data of the said registry entry is 2.)

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\Currentversion\Uninstall\
SafeSearch

HKEY_CURRENT_USER\Software\Microsoft\
Windows\Currentversion\Uninstall\
SafeSearch

Dropping Routine

This Trojan drops the following files:

• %User Profile%\Microsoft\Crypto
• %User Profile%\Crypto\RSA
• %User Profile%\RSA\S-1-5-21-4025279379-4087772427-2915903831-500
• %User Profile%\RSA\MachineKeys
• %User Temp%\WK_1.tmp
• %User Temp%\WK_2.tmp

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.. %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.)

Other Details

This Trojan connects to the following possibly malicious URL:

• http://w.{BLOCKED}ejtudlk-dfjkeid.com/wk/getclientid.wnk?{random characters}
• http://w.{BLOCKED}ejtudlk-dfjkeid.com/wk/getclientinfo.wnk?{random characters}

This report is generated via an automated analysis system.