Discovered: September 22, 2017
Updated: September 26, 2017 2:25:31 PM
Infection Length: Varies
Systems Affected: Linux
Linux.Proxym is a Trojan horse that downloads potentially malicious files onto the compromised computer.
Antivirus Protection Dates
- Initial Rapid Release version September 22, 2017 revision 022
- Latest Rapid Release version May 11, 2018 revision 039
- Initial Daily Certified version September 23, 2017 revision 001
- Latest Daily Certified version May 12, 2018 revision 003
- Initial Weekly Certified release date September 27, 2017
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.
This Trojan infects poorly secured routers.
Supported architectures include, but is not limited to, the following:
The Trojan connects to the following remote location over HTTP or FTP:
The Trojan then starts a proxy which can forward HTTP and SMTP traffic.
The Trojan may then download potentially malicious files onto the compromised computer.
The Trojan may be used to send spam emails.
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.
The following instructions pertain to Symantec AntiVirus for Linux.
- Update the virus definitions.
- 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.
Writeup By: Benjamin Moench