ThreatExpert Report: Email-Worm.Brontok!sd5, W32.Rontokbro@mm, Email-Worm.Win32.Brontok.q..

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Submission Summary:

Submission details:

Submission received: 7 September 2008, 14:46:09
Processing time: 5 min 3 sec
Submitted sample:

File MD5: 0x5128CC5C36E2DF3B2AE80E34F3809EB5
File SHA-1: 0xF24F4E00A7D7B8E21AAA5AF6526E439A745FBB25
Filesize: 45,446 bytes
Alias:

Email-Worm.Brontok!sd5 [PCTools]
W32.Rontokbro@mm [Symantec]
Email-Worm.Win32.Brontok.q [Kaspersky Lab]
W32/Rontokbro.gen@MM [McAfee]
WORM_RONTKBR.GEN [Trend Micro]
W32/Brontok-Gen, Mal/Heuri-D, Mal/EncPk-BA [Sophos]

Summary of the findings:

What's been found	Severity Level
Downloads/requests other files from Internet.
Modifies some system settings that may have negative impact on overall system security state.
Creates a startup registry entry.
Contains characteristics of an identified security risk.

Technical Details:

Possible Security Risk

Attention! Characteristics of the following security risk was identified in the system:

Security Risk	Description
Email-Worm.Brontok!sd5	Email-Worm.Brontok!sd5 is a mass-mailing application that propagates from one system to another by creating a new email message, attaching itself and then sending the message without user's consent.

Attention! The following threat category was identified:

Threat Category	Description
	A network-aware worm that attempts to replicate across the existing network(s)

File System Modifications

The following files were created in the system:

#	Filename(s)	File Size	File Hash	Alias
1	%AppData%\br6657on.exe %AppData%\csrss.exe %AppData%\inetinfo.exe %AppData%\lsass.exe %AppData%\services.exe %AppData%\smss.exe %AppData%\svchost.exe %AppData%\winlogon.exe %Programs%\Startup\Empty.pif %Templates%\11496-NendangBro.com %Windir%\KesenjanganSosial.exe %Windir%\ShellNew\RakyatKelaparan.exe %System%\cmd-brontok.exe [file and pathname of the sample #1] %System%\%UserName%'s Setting.scr	45,446 bytes	MD5: 0x5128CC5C36E2DF3B2AE80E34F3809EB5 SHA-1: 0xF24F4E00A7D7B8E21AAA5AF6526E439A745FBB25	Email-Worm.Brontok!sd5 [PCTools] W32.Rontokbro@mm [Symantec] Email-Worm.Win32.Brontok.q [Kaspersky Lab] W32/Rontokbro.gen@MM [McAfee] WORM_RONTKBR.GEN [Trend Micro] W32/Brontok-Gen, Mal/Heuri-D, Mal/EncPk-BA [Sophos]
2	%Windir%\Tasks\At1.job	416 bytes	MD5: 0xC57CAF4523A1036BA1A65B6F83A945A1 SHA-1: 0xB932FDBA7C1D2C75FC14C4EF0C5D184626CDFBC1	(not available)
3	%Windir%\Tasks\At2.job	416 bytes	MD5: 0x277170EFC03AC9CC064D0C4810EF66AE SHA-1: 0x39DCFB804FD8A90E7AB14CBBBE64573767D880E1	(not available)

Notes:

%AppData% is a variable that refers to the file system directory that serves as a common repository for application-specific data. A typical path is C:\Documents and Settings\[UserName]\Application Data.
%Programs% is a variable that refers to the file system directory that contains the user's program groups. A typical path is C:\Documents and Settings\[UserName]\Start Menu\Programs.
%Templates% is a variable that refers to the file system directory that serves as a common repository for document templates. A typical path is C:\Documents and Settings\[UserName]\Templates.
%Windir% is a variable that refers to the Windows installation folder. By default, this is C:\Windows or C:\Winnt.
%System% is a variable that refers to the System folder. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).
%UserName% is a variable that refers to the current user name.

The following file was modified:

c:\AUTOEXEC.BAT

The following directories were created:

%AppData%\Bron.tok-17-7
%Windir%\ShellNew

Memory Modifications

There were new processes created in the system:

Process Name	Process Filename	Main Module Size
winlogon.exe	%AppData%\winlogon.exe	270,336 bytes
services.exe	%AppData%\services.exe	270,336 bytes
lsass.exe	%AppData%\lsass.exe	270,336 bytes
cmd-brontok.exe	%System%\cmd-brontok.exe	270,336 bytes
smss.exe	%AppData%\smss.exe	270,336 bytes
rakyatkelaparan.exe	%Windir%\shellnew\rakyatkelaparan.exe	270,336 bytes
kesenjangansosial.exe	%Windir%\kesenjangansosial.exe	270,336 bytes
br6657on.exe	%AppData%\br6657on.exe	270,336 bytes
[filename of the sample #1]	[file and pathname of the sample #1]	270,336 bytes
%UserName%'s setting.scr	%System%\%UserName%'s setting.scr	270,336 bytes
inetinfo.exe	%AppData%\inetinfo.exe	270,336 bytes

Registry Modifications

The following Registry Key was created:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System

The newly created Registry Values are:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]

Bron-Spizaetus = ""%Windir%\ShellNew\RakyatKelaparan.exe""

so that RakyatKelaparan.exe runs every time Windows starts

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer]

NoFolderOptions = 0x00000001

to remove the Folder Options item from all Windows Explorer menus and from Control Panel

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System]

DisableRegistryTools = 0x00000001
DisableCMD = 0x00000000

to disable the Windows registry editors (Regedt32.exe and Regedit.exe)

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run]

Tok-Cirrhatus-2817 = ""%AppData%\br6657on.exe""
Tok-Cirrhatus = ""

so that br6657on.exe runs every time Windows starts

The following Registry Values were modified:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon]

Shell = "Explorer.exe "%Windir%\KesenjanganSosial.exe""

so that KesenjanganSosial.exe runs every time Windows starts

[HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\SafeBoot]

AlternateShell = "cmd-brontok.exe"

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SafeBoot]

AlternateShell = "cmd-brontok.exe"

Other details

To mark the presence in the system, the following Mutex objects were created:

userenv: user policy mutex
userenv: User Registry policy mutex

The following Host Name was requested from a host database:

google.com

The data identified by the following URLs was then requested from the remote web server:

http://www.20mbweb.com/News/cmbrotlu3/IN17.css
http://www.20mbweb.com/News/cmbrotlu3/Host17.css

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