PHP.Anuna

Risk Level 1: Very Low

Discovered:
November 19, 2015
Updated:
April 22, 2016 1:50:30 PM
Type:
Trojan
Infection Length:
13,200 bytes
Systems Affected:
Linux, Mac, Solaris, Windows

SUMMARY

PHP.Anuna is a PHP Trojan horse that injects malicious code into PHP files stored on compromised web servers.

Antivirus Protection Dates

  • Initial Rapid Release version November 19, 2015 revision 008
  • Latest Rapid Release version December 13, 2016 revision 017
  • Initial Daily Certified version November 19, 2015 revision 017
  • Latest Daily Certified version December 14, 2016 revision 002
  • Initial Weekly Certified release date November 25, 2015
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

TECHNICAL DETAILS

The Trojan's malicious code has been seen to be added to WordPress PHP files on compromised web servers. The attackers may have used another tool or script to add this heavily obfuscated malicious code to the affected files.

The Trojan connects to the following remote locations:
  • 33db9538.com
  • 9507c4e8.com
  • e5b57288.com
  • 54dfa1cb.com

Next, the Trojan receives malicious code from these remote locations and injects it into the body of a web page.

The Trojan does not perform any malicious activities if the PHP file's User Agent has one of the following strings:
  • google
  • slurp
  • msnbot
  • ia_archiver
  • yandex
  • rambler

The Trojan also doesn't act if the PHP file name has the following string:
  • admin

The Trojan then sends the following information about compromised PHP files to the remote locations:
  • User Agent
  • HTTP referrer
  • HTTP host
  • Remote IP address
  • Infected PHP file name

If a user visits a web page containing an infected PHP file, then malicious code may execute on their computer.

Recommendations

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.

REMOVAL

You may have arrived at this page either because you have been alerted by your Symantec product about this risk, or you are concerned that your computer has been affected by this risk.

Before proceeding further we recommend that you run a full system scan. If that does not resolve the problem you can try one of the options available below.

Windows
FOR NORTON USERS
If you are a Norton product user, we recommend you try the following resources to remove this risk.


Removal Tool

If you have an infected Windows system file, you may need to replace it using the Windows installation CD.


How to reduce the risk of infection
The following resources provide further information and best practices to help reduce the risk of infection.


FOR BUSINESS USERS
If you are a Symantec business product user, we recommend you try the following resources to remove this risk.


Identifying and submitting suspect files
Submitting suspicious files to Symantec allows us to ensure that our protection capabilities keep up with the ever-changing threat landscape. Submitted files are analyzed by Symantec Security Response and, where necessary, updated definitions are immediately distributed through LiveUpdateâ„¢ to all Symantec end points. This ensures that other computers nearby are protected from attack. The following resources may help in identifying suspicious files for submission to Symantec.


Removal Tool

If you have an infected Windows system file, you may need to replace it using the Windows installation CD.


How to reduce the risk of infection
The following resource provides further information and best practices to help reduce the risk of infection.
Protecting your business network



MANUAL REMOVAL
The following instructions pertain to all current Symantec antivirus products.


1. Performing a full system scan
How to run a full system scan using your Symantec product


2. Restoring settings in the registry
Many risks make modifications to the registry, which could impact the functionality or performance of the compromised computer. While many of these modifications can be restored through various Windows components, it may be necessary to edit the registry. See in the Technical Details of this writeup for information about which registry keys were created or modified. Delete registry subkeys and entries created by the risk and return all modified registry entries to their previous values.

Macintosh
The following instructions pertain to all current and recent Symantec antivirus products for Macintosh.
  1. Update the virus definitions.
  2. Run a full system scan and repair or delete all the files detected.
For specific details on each of these steps, read the following instructions.

1. To update the virus definitions
To obtain the most recent virus definitions run LiveUpdate: These virus definitions are posted to the LiveUpdate servers regularly. To determine whether definitions for this threat are available by LiveUpdate, refer to the Virus Definitions (LiveUpdate).

2. To scan for and delete the infected files
  • Start your Norton AntiVirus or Symantec Endpoint Protection for Macintosh program and make sure that it is configured to scan all files.
  • Run a full system scan.
  • If any files are detected, click Repair (if available) or Delete.

Linux
The following instructions pertain to Symantec AntiVirus for Linux.

  1. Update the virus definitions.
  2. Run a full system scan.

1. To update the virus definitions
To obtain the most recent virus definitions run LiveUpdate. For Symantec AntiVirus for Linux, LiveUpdate definitions are updated regularly.

2. To run a full system scan
To run a full system scan in Linux, open a command line and type the following:

sav manualscan --scan /

If any files are detected, follow the instructions displayed by your antivirus program.