||W32.HLLP.Systemp is a parasitic virus written in C++ (a high-level language), using the MFC libraries. Once W32.HLLP.Systemp is executed, it will insert a backdoor on the user's system.
Infection Length: 78582 bytes
Systems Affected: Windows 95, Windows 98, Windows NT, Windows 2000, Windows XP, Windows Me
Systems Not Affected: Windows 3.x, Macintosh, OS/2, UNIX, Linux
When W32.HLLP.Systemp is executed, it performs the following actions:
1. Creates the following files
%Windir% is a variable. The virus locates the Windows installation folder (by default, this is C:\Windows or C:\Winnt) and copies itself to that location.
%System% is a variable. The virus locates the System folder and copies itself to that location. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).
2. Adds the value:
to the registry key:
3. On Windows 9x/Me systems, W32.HLLP.Systemp will also delete the registry value: SysTray
under the registry key:
4. Then, W32.HLLP.Systemp will create a duplicate host file, with the Hidden attribute set, in the same location as the infected file, as
ÿ<name of infected file>
Then, W32.HLLP.Systemp will proceed to execute the original host.
NOTE: This duplicate host file is not binary-compatible with the original host file, as the virus changes its icon to the one used for the files with no association.
5. Proceeds to infect files with the .exe file extension on the current hard drive.
Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":
Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
If a blended threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
Isolate infected computers quickly to prevent further compromising your organization. Perform a forensic analysis and restore the computers using trusted media.
Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched
The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.
1. Update the virus definitions.
2. Do one of the following:
Windows 95/98/Me: Restart the computer in Safe mode.
Windows NT/2000/XP: End the Trojan process.
3. Run a full system scan. Delete all the files detected as Backdoor.Trojan and repair all the files detected as W32.HLLP.Systemp.
4. Reverse the changes that the Trojan made to the registry.
5. Delete the following files:
Any files starting with the character ÿ
For details on each of these steps, read the following instructions.
1. Updating the virus definitions
Symantec Security Response fully tests all the virus definitions for quality assurance before they are posted to our servers. There are two ways to obtain the most recent virus definitions:
Running LiveUpdate, which is the easiest way to obtain virus definitions: These virus definitions are posted to the LiveUpdate servers once each week (usually on Wednesdays), unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, refer to the Virus Definitions (LiveUpdate).
Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). You should download the definitions from the Symantec Security Response Web site and manually install them. To determine whether definitions for this threat are available by the Intelligent Updater, refer to the Virus Definitions (Intelligent Updater).
The Intelligent Updater virus definitions are available here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.
2. Restarting the computer in Safe mode or ending the Trojan process
Restart the computer in Safe mode. All the Windows 32-bit operating systems, except for Windows NT, can be restarted in Safe mode. For instructions on how to do this, read the document, "How to start the computer in Safe Mode."
To end the Trojan process:
a. Press Ctrl+Alt+Delete once.
b. Click Task Manager.
c. Click the Processes tab.
d. Double-click the Image Name column header to alphabetically sort the processes.
e. Scroll through the list and look for Systray.exe.
f. If you find the file, click it, and then click End Process.
g. Exit the Task Manager.
3. Scanning for and deleting the infected files
a. Start your Symantec antivirus program and make sure that it is configured to scan all the files.
For Norton AntiVirus consumer products: Read the document, "How to configure Norton AntiVirus to scan all files."
For Symantec AntiVirus Enterprise products: Read the document, "How to verify that a Symantec Corporate antivirus product is set to scan All Files."
b. Run a full system scan.
c. If any files are detected as infected with Backdoor.Trojan, click Delete.
d. If any files are detected as infected with W32.HLLP.Systemp, click Repair.
4. Reversing the changes made to the registry
CAUTION: Symantec strongly recommends that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify the specified keys only. Read the document, "How to make a backup of the Windows registry," for instructions.
a. Click Start, and then click Run. (The Run dialog box appears.)
b. Type regedit
Then click OK. (The Registry Editor opens.)
c. Navigate to the key:
d. Do one of the following:
Windows 98/Me: In the right pane, double-click the value, SysTray. Change the Value Data to SysTray.exe, and then click OK.
Windows NT/2000/XP: In the right pane, delete the value, SysTray.
e. Exit the Registry Editor.
5. Deleting the files
Ensure that Explorer is set to Show All Files:
To configure Windows to show all the files:
a. Start Windows Explorer.
b. Click the View menu (Windows 95/98/NT) or the Tools menu (Windows Me/2000/XP), and then click Options or "Folder options."
c. Click the View tab.
d. Uncheck "Hide file extensions for known file types."
e. Do one of the following:
Windows 95/NT: Click "Show all files."
Windows 98: In the Advanced settings box, under the "Hidden files" folder, click Show all files.
Windows Me/2000/XP: Uncheck "Hide protected operating system files," and under the "Hidden files" folder, click "Show hidden files and folders."
f. Click Yes if you see a Warning dialog box.
g. Click Apply, and then click OK.
Follow the instructions for your operating system:
a. Click Start, point to Find or Search, and then click Files or Folders.
b. Make sure that "Look in" is set to (C:) and that "Include subfolders" is checked.
c. In the "Named" or "Search for..." box, type, or copy and paste, the following filenames:
sysddzg.dll ~temddz ÿ
d. Click Find Now or Search Now.
e. Delete the displayed files.
a. Click Start, and then click Search.
b. Click All files and folders.
c. In the "All or part of the file name" box, type, or copy and paste, the following filenames:
sysddzg.dll ~temddz ÿ
d. Verify that "Look in" is set to "Local Hard Drives," or to (C:).
e. Click "More advanced options."
f. Check "Search system folders."
g. Check "Search subfolders."
h. Click Search.
i. Delete the displayed files.