Linux.Shishiga

Printer Friendly Page

Discovered: April 26, 2017
Updated: May 04, 2017 2:32:39 PM
Type: Worm
Infection Length: Varies
Systems Affected: Linux

Linux.Shishiga is a worm that opens a backdoor on the compromised computer and downloads potentially malicious files.

Antivirus Protection Dates

  • Initial Rapid Release version April 26, 2017 revision 001
  • Latest Rapid Release version April 26, 2018 revision 036
  • Initial Daily Certified version April 26, 2017 revision 005
  • Latest Daily Certified version April 27, 2018 revision 003
  • Initial Weekly Certified release date May 03, 2017

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Writeup By: Ke Zhang

Discovered: April 26, 2017
Updated: May 04, 2017 2:32:39 PM
Type: Worm
Infection Length: Varies
Systems Affected: Linux

The worm spreads by brute forcing Telnet and SSH credentials.

The worm creates the following files:

  • $home/.local/nodes.cfg
  • $home/.local/script.bt
  • $home/.local/syslog.pid
  • $home/.local/server.bt
  • $home/.local/ssh.txt
  • $home/.local/syslogd
  • $home/.local/update.bt
  • /etc/init.d/[THREAT FILE NAME]
  • /etc/rc2.d/[THREAT FILE NAME]
  • /etc/rc3.d/[THREAT FILE NAME]
  • /etc/rc4.d/[THREAT FILE NAME]
  • /etc/rc5.d/[THREAT FILE NAME]
  • /etc/cron.hourly/[THREAT FILE NAME]

The worm opens a backdoor on the compromised computer and connects to the following remote location over TCP port 8080:
  • 93.117.137.35

The worm may then perform the following actions on the compromised computer:
  • Scan and infect other computers on randomly generated external network addresses
  • Download additional modules
  • Upload files to a remote location

The Trojan sends the following information about newly infected computers to a remote location:
  • IP address
  • Port number
  • User name and password used to log in successfully
  • CPU architecture


    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.

    Writeup By: Ke Zhang

    Discovered: April 26, 2017
    Updated: May 04, 2017 2:32:39 PM
    Type: Worm
    Infection Length: Varies
    Systems Affected: 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.

    Writeup By: Ke Zhang