How to stay protected against ransomware

Businesses are under threat from increasingly aggressive and brutal ransomware attacks. Loss of access to critical files, followed by a demand for payment, can cause massive disruption to an organisation’s productivity. But what does a typical attack look like? And what security solutions should be in place to give the best possible defence?

“Sophos has compiled information that will help businesses gear up against ransomware attacks. The company discusses the commonly used techniques to deliver ransomware and why these attacks are succeeding. In addition, it provides 10 security recommendations to help you stay secure and highlights the critical security technologies that every IT set-up should include,” says Ross Anderson, Sophos Product Development Manager at Duxbury Networking.

The current wave of ransomware families have roots traced back to the early days of Fake AV, through ‘Locker’ variants and finally to the file-encrypting variants that are prevalent today. Each distinct category of malware has shared a common goal – to extort money from victims through social engineering and outright intimidation. The demands for money have grown more forceful and audacious with each iteration, with some hackers now demanding millions.

Despite rumours of the demise of ransomware, it is still very much alive and kicking. A Sophos survey of 3 100 organisations found that 30% of cyber attack victims had been hit by ransomware. Additionally, and of concern, nine in 10 respondents said their organisation was running up-to-date cyber security protection at the time of the attack.

Most organisations have at least some form of IT security in place. So why are ransomware attacks slipping through the net?

1. Hacking is becoming easier while attackers are becoming more sophisticated in their approach.

• 'Exploit as a service' (EaaS) programs that take advantage of vulnerabilities in existing software products are increasingly accessible. These kits make it simple for less tech-savvy criminals to initiate, complete and benefit from a ransomware attack.
• Criminals use skilful social engineering to prompt users to run the ransomware’s installation routine. They try to trick users into activating the ransomware with e-mails that encourage the recipient to click on a link or open a file, for example: “My organisation’s requirements are in the attached file. Please provide me with a quote.”
• Producers of ransomware operate in a highly organised fashion. This includes providing a working decryption tool after the ransom has been paid, although this is by no means guaranteed.

2. Security problems at affected companies.

• Systems are often unpatched, leaving them unnecessarily vulnerable to threats.
• Inadequate backup strategy and lack of disaster recovery practice/plan (backups not offline/off-site).
• Updates/patches for operating system and applications are not implemented swiftly enough or at all.
• Dangerous user permissions (users work as administrators and/or have more file rights on network drives than necessary for their tasks).
• Lack of user security training (“Which documents may I open and from whom?”, “What is the procedure if a document looks malicious?”, “How do I recognise a phishing email?”)
• Lack of layered security strategy so attackers often only need to overcome a single hurdle.
• Inconsistent or incomplete security policies that leave gaps through which attackers can enter.
• Conflicting priorities (“We know that this method is not secure, but our people have to work…”)
• Poorly configured IT security (badly regulated external access, for example, Remote Desktop Protocol exposed).

There are multiple ways that a ransomware attack starts. Common techniques include:

• Malicious e-mails;
• Poisoned websites redirecting you to exploit kits; and
• Remote Desktop Protocol (RDP) and other remote access holes.

After initial exposure, attacks typically fall into two different categories:

1. ‘Fire and forget’. These types of automated attacks target multiple organisations with the hope of securing a high quantity of smaller ransoms. Think back to WannaCry. Thousands and thousands of organisations were hit by WannaCry at the same time. These hackers use automated, ‘fire and forget’ techniques, where the attack is launched and spread to as many computers as possible. Due to the automation and number of attacks, the attacker is oblivious to the stages of the attack.
2. Targeted ransomware. Targeted ransomware is a very manual attack, typically focuses on one victim at a time, and often demands much higher ransom fees. The attackers gain access to the network and move laterally, identifying high-value systems in the process. Strains of this type of ransomware overcome challenges as they arise, making them particularly deadly.

Staying secure against ransomware isn’t just about having the latest security solutions. Good IT security practices, including regular training for employees, are essential components of every single security set-up. Make sure you’re following these 10 best practices:

1. Patch early, patch often. Malware that doesn’t come in via a document often relies on security bugs in popular applications, including Microsoft Office, your browser, Flash and more. The sooner you patch, the fewer holes there are to be exploited.
2. Backup regularly and keep a recent backup copy offline and off-site. There are dozens of ways other than ransomware that files can suddenly vanish, such as fire, flood, theft, a dropped laptop or even an accidental delete. Encrypt your backup and you won’t have to worry about the backup device falling into the wrong hands. Furthermore, a disaster recovery plan that covers the restoration of data and whole systems.
3. Enable file extensions. The default Windows setting is to have file extensions disabled, meaning you must rely on the file thumbnail to identify it. Enabling extensions makes it much easier to spot file types that wouldn’t commonly be sent to you and your users, such as JavaScript.
4. Open JavaScript (.JS) files in Notepad. Opening a JavaScript file in Notepad blocks it from running any malicious scripts and allows you to examine the file contents.
5. Don’t enable macros in document attachments received via e-mail. Microsoft deliberately turned off auto-execution of macros by default many years ago as a security measure. A lot of infections rely on persuading you to turn macros back on, so don’t do it!
6. Be cautious about unsolicited attachments. The crooks are relying on the dilemma you face knowing that you shouldn’t open a document until you are sure it’s one you want, but you can’t tell if it’s one you want until you open it. If in doubt, leave it out.
7. Monitor administrator rights. Constantly review admin and domain admin rights. Know who has them and remove those who do not need them. Don’t stay logged in as an administrator any longer than is strictly necessary and avoid browsing, opening documents or other regular work activities while you have administrator rights.
8. Stay up to date with new security features in your business applications. For example, Office 2016 now includes a control called: “Block macros from running in Office files from the internet,” which helps protect against external malicious content without stopping you from using macros internally.
9. Regulate external network access. Don’t leave ports exposed to the world. Lock down your organisation’s RDP access and other management protocols. Furthermore, use two-factor authentication and ensure remote users authenticate against a VPN.
10. Use strong passwords. It sounds trivial, but it really isn’t. A weak and predictable password can give hackers access to your entire network in a matter of seconds. We recommend making them impersonal, at least 12 characters long, using a mix of upper and lower case and adding a sprinkle of random punctuation Ju5t.LiKETh1s!

To stop ransomware, you need to have effective and advanced protection in place at every stage of an attack. Sophos XG Firewall is packed with technology to help protect your organisation from ever-evolving ransomware attacks. In particular, XG Firewall includes one of the best performing and most effective IPS engines on the market and provides a simple and elegant solution to lock down your RDP servers.

XG Firewall offers flexible and easy segmentation tools like zones and VLANs to secure your LAN and reduce the risk of lateral movement, reducing surface area of attack and minimising the risk and potential scope of propagation.

Should hackers somehow access your network, Intercept X uses multiple layers of defence to stop ransomware in its tracks. Anti-exploit technology stops the delivery of ransomware, deep learning blocks ransomware before it can run and CryptoGuard prevents the malicious encryption of files, rolling them back to their safe state. The endpoint detection and response (EDR) functionality within Intercept X additionally detects advanced ransomware attacks that may have gone unnoticed and search for indicators of compromise across your network.

Furthermore, Sophos Managed Threat Response (MTR) enables 24/7 threat response actions to be identified and executed, utilising a fusion of machine and machine intelligence.

Sophos Phish Threat sends simulated phishing attacks to your organisation, testing preparedness against real world attacks. E-mails can be customised to your organisation and industry and have been carefully localised for multiple languages. Detailed feedback lets you see how many users failed, overall susceptibility to attacks and more.

For more information, contact Duxbury Networking, (+27) 011 351 9800, info@duxnet.co.za, www.duxbury.co.za.