Trojan:Win32/Daonol.I is a trojan that modifies Windows settings, monitors network traffic, redirects Web searches, steals FTP credentials, prevents access to certain websites and blocks execution of certain programs.
System changes
The following system changes may indicate the presence of this malware:
Trojan:Win32/Daonol.I is a trojan that modifies Windows settings, monitors network traffic, redirects Web searches, steals FTP credentials, prevents access to certain websites and blocks execution of certain programs.
Installation
Upon execution, Win32/Daonol.I drops its DLL file component with a random file name one level up from the current folder. For example, it may drop the file tpqnh.hmq in the default Windows folder if the current folder is the Windows system folder.
It then modifies the system registry so that its dropped file is registered as a Windows NT dynamic-link library for applications, for example:
Adds value: "midi9"
With data: "C:\Windows\..\tpqnh.hmq"
To subkey: HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Drivers32
Adds value: "AppInit_DLLs"
With data: "winmm.dll"
To subkey: HKLM\Software\Microsoft\Windows NT\CurrentVersion\Windows
Adds value: "LoadAppInit_DLLS"
With data: "1"
To subkey: HKLM\Software\Microsoft\Windows NT\CurrentVersion\Windows
Note: winmm.dll is a Windows system file that supports multimedia services. By registering the DLL to load at Windows start, it in turn will load drivers registered as sound drivers designated in the registry by values "midi#" and "aux#" where "#" is an optional digit 0 through 9.
Payload
Monitors network and system activities
Trojan:Win32/Daonol.I hooks the following APIs to monitor network and system activities, such as process creation, TCP network traffic, and registry entries:
kernel32!CreateProcessW
kernel32!ExitProcess
ntdll!ZwOpenKey
ws2_32.dll!recv
ws2_32.dll!send
ws2_32.dll!connect
ws2_32.dll!WSARecv
ws2_32.dll!WSASend
Avoids detection
Trojan:Win32/Daonol.I has several ways of avoiding detection. It disables access to the registry keys related to itself. It also uninstalls itself if it finds a process that creates the following strings; these strings are likely related to anti-rootkit tools:
Trojan:Win32/Daonol.I also uninstalls itself if the following string is found in the outbound network package:
It also prevents certain security-related processes from being run if their names contain any of the following strings:
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IceWord
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Rootkit Unhooker
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Anti rootkit
Trojan:Win32/Daonol.I prevents processes from running commands that contain any of the following strings:
Blocks network traffic
Trojan:Win32/Daonol.I blocks the outbound network traffic if the 'User-Agent' field of HTTP requests start with any of the following strings:
<UA
Adob
Anti
AVPU
CAUp
COMO
Enig
ESS
LIVE
McHT
NOD3
Nort
Pand
SpyS
SUPE
TMUF
It also blocks the outbound network traffic if the HTTP request refers to a host that contains any of the following strings, which may be security-related:
clamav
Malwarebytes
mcafee
prevx
Gathers FTP credentials
Trojan:Win32/Daonol.I captures users' FTP credentials by monitoring the outbound network traffic.
Redirects search traffic
Trojan:Win32/Daonol.I redirects the network traffic to a certain Web site if the URL contains any of following strings:
rds.yahoo
search
search.yahoo.
www.bing.com
www.google
.
yimg
Analysis by Tim Liu
Take the following steps to help prevent infection on your system:
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Enable a firewall on your computer.
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Get the latest computer updates for all your installed software.
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Use up-to-date antivirus software.
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Use caution when opening attachments and accepting file transfers.
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Use caution when clicking on links to web pages.
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Avoid downloading pirated software.
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Protect yourself against social engineering attacks.
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Use strong passwords.
Enable a firewall on your computer
Use a third-party firewall product or turn on the Microsoft Windows Internet Connection Firewall.
To turn on the Windows Firewall in Windows Vista
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Click Start, and click Control Panel.
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Click Security.
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Click Turn Windows Firewall on or off.
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Select On.
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Click OK.
To turn on the Internet Connection Firewall in Windows XP
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Click Start, and click Control Panel.
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Click Network and Internet Connections. If you do not see Network and Internet Connections, click Switch to Category View.
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Click Change Windows Firewall Settings.
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Select On.
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Click OK.
Get the latest computer updates
Updates help protect your computer from viruses, worms, and other threats as they are discovered. It is important to install updates for all the software that is installed in your computer. These are usually available from vendor websites.
You can use the Automatic Updates feature in Windows to automatically download future Microsoft security updates while your computer is on and connected to the Internet.
To turn on Automatic Updates in Windows Vista
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Click Start, and click Control Panel.
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Click System and Maintainance.
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Click Windows Updates.
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Select a setting. Microsoft recommends selecting Install updates automatically and choose a time that is convenient for you. If you do not choose Automatic, but you choose to be notified when updates are ready, a notification balloon appears when new downloads are available to install. Click the notification balloon to review and install the updates.
To turn on Automatic Updates in Windows XP
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Click Start, and click Control Panel.
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Click System.
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Click Automatic Updates.
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Select a setting. Microsoft recommends selecting Automatic. If you do not choose Automatic, but you choose to be notified when updates are ready, a notification balloon appears when new downloads are available to install. Click the notification balloon to review and install the updates.
Use up-to-date antivirus software
Use caution when opening attachments and accepting file transfers
Exercise caution with e-mail and attachments received from unknown sources, or received unexpectedly from known sources. Use extreme caution when accepting file transfers from known or unknown sources.
Use caution when clicking on links to Web pages
Exercise caution with links to web pages that you receive from unknown sources, especially if the links are to a Web page that you are not familiar with, unsure of the destination of, or suspicious of. Malicious software may be installed in your system simply by visiting a Web page with harmful content.
Avoid downloading pirated software
Threats may also be bundled with software and files that are available for download on various torrent sites. Downloading "cracked" or "pirated" software from these sites carries not only the risk of being infected with malware, but is also illegal. For more information, see '
The risks of obtaining and using pirated software'.
Protect yourself from social engineering attacks
While attackers may attempt to exploit vulnerabilities in hardware or software in order to compromise a system, they also attempt to exploit vulnerabilities in human behavior in order to do the same. When an attacker attempts to take advantage of human behavior in order to persuade the affected user to perform an action of the attacker's choice, it is known as 'social engineering'. Essentially, social engineering is an attack against the human interface of the targeted system. For more information, see '
What is social engineering?'.
Use strong passwords
Attackers may try to gain access to your Windows account by guessing your password. It is therefore important that you use a strong password – one that cannot be easily guessed by an attacker. A strong password is one that has at least 8 characters, and combines letters, numbers, and symbols. For more information, see
http://www.microsoft.com/protect/yourself/password/create.mspx.
Additional Recovery Instructions for Windows XP Systems
Steps to manually clean Win32/Daonol infections from within Windows XP:
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Navigate to Start, click Run, and type the following instruction:
explorer.exe c:\
then click OK or press Enter.
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Create a folder named cleanup - from the File menu, select New and then Folder and type cleanup . Press Enter twice to open the newly created folder named cleanup, or double-click on the folder.
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Navigate to Start, click Run, and type the following instruction:
explorer.exe %windir%\system32
then click OK or press Enter. Note that %windir% is intentional and points to the Windows directory as installed on the computer.
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In the list of files, look for cmd.exe. Right-click on the file and select Copy, or press Ctrl-C to copy the program to the Windows clipboard.
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Paste the copied file into the cleanup folder - press Alt-Tab to toggle the active window to the cleanup folder and press Ctrl-V to paste the cmd.exe file into this folder.
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Rename the copied cmd.exe executable to c.exe - right-click the copied file and select Rename, and type c.exe.
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Double-click c.exe to open the copied command prompt and type the following instructions in order:
copy %windir%\system32\reg.exe r.exe
r.exe save "HKLM\Software\Microsoft\Windows NT\CurrentVersion" temp.dat
r.exe load HKLM\TempCleanup temp.dat
r.exe query HKLM\TempCleanup\Drivers32
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The last instruction should result in the display of registry values. Malicious registry values will have the following common properties:
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The file name has the extension .bak, .tmp, .old or .dat
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The file path includes the full path including drive letter
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The file path includes the string \..\
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The value data may include some random strings such as 0yAAAAAAA
Note that in this example, the last entry is the malicious registry value:
midimapper REG_SZ midimap.dll
vidc.iv32 REG_SZ ir32_32.dll
vidc.iv41 REG_SZ ir41_32.ax
midi9 REG_SZ C:\Windows\..\kft.bak 0yAAAAAAAA
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Write down the malicious registry value and data details on paper, as in the following example:
value = midi9
file = C:\Windows\..\kft.bak
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Type the following instructions to delete the malicious registry key:
r.exe delete “HKLM\Software\Microsoft\Windows NT\CurrentVersion” /v <value>
where <value> is the value that you have written down in step 9. For the above example the instruction would be:
r.exe delete “HKLM\Software\Microsoft\Windows NT\CurrentVersion” /v midi9
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Delete the Win32/Daonol file by typing the following instruction:
delete "C:\Windows\..\<file>"
where <file> is the value that you have written down in step 9. For the above example the instruction would be:
delete "C:\Windows\..\kft.bak"
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Restart your computer.
