Call us today on: +44 (0)203 88 020 88
SecureTeamSecureTeamSecureTeamSecureTeam
  • Home
  • Our Services
    • Infrastructure Testing
      • Internal Network Penetration Test
      • External Network Penetration Test
      • Wireless Network Penetration Test
      • Vulnerability Assessment
      • Network Segregation Test
      • Voice over IP (VoIP) Penetration Test
    • Application Testing
      • Web Application Penetration Test
      • Mobile Application Penetration Test
      • Desktop Application Security Assessment
      • Citrix Breakout Test
    • Configuration Review
      • Windows Server Build Review
      • Linux Server Build Review
      • Citrix Configuration Review
    • Information Assurance
      • ISO 27001 Gap Analysis
    • Cyber Essentials
  • News
  • Articles
  • About
    • About SecureTeam
    • STORM Appliances
      • Installing a STORM Device
      • Returning a STORM Device
    • White-Label Consultancy
    • Jobs
    • Cookie Policy
    • Privacy Notice
    • Website Terms & Conditions
  • Contact Us

News

Home  >  News  >  Tools  >  How to defend against the RATdispenser
NextPrevious

How to defend against the RATdispenser

News, Tools | 1 December, 2021 | 0

A new report from HP’s Threat Research Blog provides details of an evasive Javascript loader that gets passed security tools 89% of the time.

Remote Access Trojans (RATs) are a class of malware that is designed to gain persistent access to the target computer system, and by leveraging elevation of privilege vulnerabilities gain administrator rights over the device and so take full control of the system and all the data on it.

RATDispenser is the name given to a JavaScript delivery system for RAT malware used by at least eight different families of malware.  RATDispenser is usually used as a self contained dropper – it does not need to communicate over the network back to any command and control servers as it already contains the malicious payload it wants to deliver.

This may sound sophisticated, but the delivery system is actually relatively simple and Security Managers can take some basic steps to harden their network against RATDispenser and similar malware.

The attack chain begins with the delivery of an email that has the malware enclosed as an attachment which uses a double file extension to allow the JavaScript file to masquerade as a text file – for example OPENME.txt.js  When the user double clicks the attachment to open the text file, the javascript will execute on Windows computers with default protections in place.

When the Javascript executes, it writes a VBSript file into a temp folder and then executes the script with a long, chained argument, which is the main payload that the VBScript writes to disk and executes.

Defend against RATDispenser

Security Managers can defend against RATDispenser and similar malware in two ways:

  • Block executable email attachments
  • Limit the running of scripts to require digitally signed scripts or block them all together.

Blocking executable email attachments can be done by following this guidance for Microsoft Exchange. Firewalls and security appliances may also have the ability to inspect incoming email and filter out malicious attachments.

If a malicious attachment does manage to get delivered to an end user, and despite their Security Awareness Training they still click on the attachment to open it, then disabling or limiting the execution of scripts will provide an additional layer of defence.

Windows Script Host can be fully disabled by adding a registry entry.  However, there may be legitimate use of Windows Scripting for system administration in which case it is possible to configure a Windows system to only allow digitally signed scripts to execute.

Note that if you have not configured Software Restriction Policies for your domain, you will first need to disable them by setting the registry for  Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Script Host\Settings\useWINSAFER to 0 and then you can set TrustPolicy to 2 (2 = only allow signed scripts or set it to 1 to always ask before running a script if it is not signed).

 

 

Subscribe to our monthly cybersecurity newsletter
Stay up-to-date with the very latest cybersecurity news & technical articles delivered straight to your inbox
We hate spam as much as you do. We will never give your email address out to any third-party.
Exchange Server, Security operations

Related Post

  • Microsoft Autodiscover protocol leaks domain credentials

    By Mark Faithfull

    A flaw in the design of the Autodiscover protocol used to set-up email clients with Exchange Server can cause domain credentials to be sent in the clear to a server controlled by an attacker. TheRead more

  • The rise and rise of BEC fraud

    By Mark Faithfull

    Business Email Compromise, and its evil brother CEO Fraud, are both email based fraud attacks that seek to trick the victim into paying a fake invoice or transferring or diverting funds through some other kindRead more

  • Top 15 Most Exploited Vulnerabilities for 2021

    By Mark Faithfull

    The 15 most targeted security vulnerabilities of 2021 have just been published in a joint advisory from the NCSC.  These are the main ways hackers are attacking businesses around the world. Cybersecurity authorities across multipleRead more

  • How to improve your supply chain security

    By Mark Faithfull

    The security of every business is dependent on the security of its suppliers.  From the PCs on peoples desks, to the servers in cloud, the firewalls in the office and the experts that connect toRead more

  • NCSC Updates Guidance on Russian cyber threat

    By Mark Faithfull

    The NCSC has issued updated guidance on the evolving threat from Russian state actors and cyber criminals due to the ongoing war in Ukraine. The joint Cybersecurity Advisory (CSA) from the cybersecurity authorities in theRead more

NextPrevious

Recent Posts

  • HTML Phishing on the rise
  • Microsoft patches critical zero-day
  • NCSC offers free email security tool
  • Top 15 Most Exploited Vulnerabilities for 2021
  • NHS Targeted in Phishing Campaign

Tags

Adobe Android Apple blockchain Bluetooth Chrome Cisco credential stuffing cyber crime cyber essentials cyber security cyber security news Data Protection DDoS Dell DNS Exchange Server exim formjacking GDPR Google IoT Linux microsoft Mozilla ncsc npm patching penetration testing phishing ransomware RDP SAP security breach Security operations security testing SIEM software development Spectre supply chain attacks Sysinternals vulnerability management web applications web browsers wireless

Archives

  • May 2022
  • April 2022
  • March 2022
  • February 2022
  • January 2022
  • December 2021
  • November 2021
  • October 2021
  • September 2021
  • August 2021
  • July 2021
  • June 2021
  • May 2021
  • April 2021
  • March 2021
  • February 2021
  • January 2021
  • December 2020
  • November 2020
  • October 2020
  • September 2020
  • August 2020
  • July 2020
  • June 2020
  • April 2020
  • March 2020
  • February 2020
  • January 2020
  • December 2019
  • November 2019
  • October 2019
  • September 2019
  • August 2019
  • July 2019
  • June 2019
  • May 2019
  • April 2019
  • March 2019
  • February 2019
  • January 2019
  • December 2018
  • November 2018
  • July 2018
  • June 2018
  • April 2018
  • January 2018
  • October 2017
BCS Cyber Essentials Cyber Essentials Cyber Essentials PLUS ISO 9001 ISO 27001
information. secured.
  • Home
  • Our Services
    • Infrastructure Testing
      • Internal Network Penetration Test
      • External Network Penetration Test
      • Wireless Network Penetration Test
      • Vulnerability Assessment
      • Network Segregation Test
      • Voice over IP (VoIP) Penetration Test
    • Application Testing
      • Web Application Penetration Test
      • Mobile Application Penetration Test
      • Desktop Application Security Assessment
      • Citrix Breakout Test
    • Configuration Review
      • Windows Server Build Review
      • Linux Server Build Review
      • Citrix Configuration Review
    • Information Assurance
      • ISO 27001 Gap Analysis
    • Cyber Essentials
  • News
  • Articles
  • About
    • About SecureTeam
    • STORM Appliances
      • Installing a STORM Device
      • Returning a STORM Device
    • White-Label Consultancy
    • Jobs
    • Cookie Policy
    • Privacy Notice
    • Website Terms & Conditions
  • Contact Us
SecureTeam