TROJ_DRPPR.KSE

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 creates registry entries to enable its automatic execution at every system startup.

It modifies the Internet Explorer Zone Settings.

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:

• %All Users Profile%\{Random File Name}.exe

(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)

It creates the following folders:

• %Application Data%\{Random Folder Name}
• %Application Data%\{Random Folder Name 2}

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

Autostart Technique

This Trojan modifies the following registry entry(ies) to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{Random GUID} = "%Application Data%\{Random Folder Name}\{Random File Name 1}.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
540 = "%All Users Profile%\{Random File Name}.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Foxix

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Foxix
{Random Subkey Name 2} = "{Random Hex Values}"

HKEY_CURRENT_USER\Software\Microsoft\
Foxix
{Random Subkey Name} = "{Random Hex Values}"

HKEY_CURRENT_USER\Software\Microsoft\
Foxix
{Random Subkey Name 3} = "{Random Hex Values}"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0
Compact Check Count = "1"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0
ConvertedToDBX = "1"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0
MSIMN = "1"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0
Running = "0"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0
Settings Upgraded = "7"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0
SpellDontIgnoreDBCS = "1"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0
SpoolerDlgPos = "{Random Hex Values}"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0
SpoolerTack = "0"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0
Store Root = "%AppDataLocal%\Identities\{Random GUID}\Microsoft\Outlook Express\"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0
StoreMigratedV5 = "1"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0
VerStamp = "3"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0\Mail
Accounts Checked = "{Random Hex Values}"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0\Mail
Default_CodePage = "28591"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0\Mail
Safe Attachments = "1"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0\Mail
Secure Safe Attachments = "1"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0\Mail
Welcome Message = "0"

HKEY_CURRENT_USER\Identities\{Random GUID}\
Software\Microsoft\Outlook Express\
5.0\News
Accounts Checked = "{Random Hex Values}"

HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
FirstRun = "1"

HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
OlkContactRefresh = "0"

HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
OlkFolderRefresh = "0"

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

Dropping Routine

This Trojan drops the following files:

• %Application Data%\{Random Folder Name}\{Random File Name 1}.exe
• %Application Data%\{Random Folder Name 2}\{Random File Name 2}.tmp
• %Application Data%\{Random Folder Name 2}\{Random File Name 2}.zec

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

Other Details

This Trojan connects to the following possibly malicious URL:

• http://{BLOCKED}es.pl
• http://{BLOCKED}y.pl
• http://{BLOCKED}ly.ru