1. Symantec/
  2. Security Response/
  3. JS.Proslikefan.B


Risk Level 1: Very Low

October 31, 2014
November 3, 2014 10:54:59 PM
Trojan, Worm
Infection Length:
43,287 KB
Systems Affected:
The worm may be spread through USB drives.

When the worm is executed, it may copy itself to the following locations:
  • %Driveletter%:\.Trashes\[CALCULATED VALUE]\[CALCULATED VALUE].js
  • %UserProfile%\Local Settings\Temp\[CALCULATED VALUE].js
  • %UserProfile%\[CALCULATED VALUE].js
  • %UserProfile%\AppData\Roaming\[CALCULATED VALUE].js

Note: [CALCULATED VALUE] is determined by the worm and may be a random number or a randomly selected piece of system information.

The worm may create the following hidden folder on USB drives:
  • %Driveletter%:\.Trashes\[CALCULATED VALUE]\

The worm may copy a clean wscript.exe to the following locations:
  • %UserProfile%\[1][2][3].exe
  • %UserProfile%AppData\Roaming\[1][2][3].exe

Note: [1][2][3] is a concatenation of several different values.

[1] may be any of the following values:
  • win
  • cmd
  • disk
  • dsk
  • ms
  • hp
  • intel
  • amd
  • dll
  • tcp
  • udp

[2] may be any of the following values:
  • process
  • proc
  • monitor
  • mon
  • sys
  • host
  • mgr
  • update
  • updater

[3] may be any of the following values:
  • 32
  • 64

The worm may modify the following registry values:
  • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Hidden = 1 or 2
  • HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\ShowSuperHidden = 0 or 1

The worm may contact one of the following non-malicious servers to determine the time:
  • https://www.microsoft.com
  • https://www.google.com
  • https://www.bing.com

The worm will check if the current date is after January 1, 2014 00:00:00 UTC.

The worm may connect to one of the following remote locations:
  • [http://][REMOVED]
  • [http://]cdn.httpowered.com[REMOVED]
  • [http://]www2.httpoptions.com[REMOVED]

The worm may quit if it detects that it is running on a virtual machine.

The worm may attempt to kill processes that are associated with detecting and removing malicious software.

The worm may modify access control lists for files used by the threat.

The worm may download updates of itself.

The worm may steal the following information and send it to a remote location:
  • User name
  • Computer name
  • Windows ProductID
  • OS language
  • OS version

The worm may create the following shortcuts that point to the worm:
  • %SystemDrive%\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup\Windows Explorer.lnk
  • %UserProfile%\Start Menu\Programs\Startup\Windows Explorer.lnk
  • %UserProfile%]\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\Windows Explorer.lnk

Note: The shortcuts may use any of the following file type icons:
  • exe
  • doc
  • docx
  • pdf
  • rtf
  • txt
  • mp3
  • m4a
  • ogg
  • wav
  • mp4
  • avi
  • webm
  • flv
  • mov
  • wmv
  • mpeg
  • mpg
  • gif
  • jpg
  • jpeg
  • png


Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • 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.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a 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.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. 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.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.
Writeup By: Fred Gutierrez
Summary| Technical Details| Removal

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