Your Step by Step Guide to Mitigating and Preventing a Ransomware Virus in your Small/Medium Business

With the recent epidemic of ransomware viruses (up over 600% in 2016 and with the newest batch of exploits wreaking havoc internationally), I thought it would be a good idea to go through the basic guidelines for mitigating and containing ransomware for your small to mid sized business. There are plenty of additional pieces to putting this together completely so please reach out to me if you would like some assistance. Some of these are simple recommendations and this is by no means a complete list. But, then again, eat healthy, exercise regularly and don’t smoke are simple recommendations – and if you don’t follow them, you know what to expect.

  1. Use a reputable multi vector end point security – Use anti virus programs like Webroot/Kaspersky/McAfee/Avast. Don’t be penny wise and pound foolish. Buy a proper license for each machine. Keep it updated for all new definitions. Keep it current and get one that is constantly being updated. No one program is going to be 100% effective. Also, make sure that you have a program that detects malware. Malwarebytes Premium is my favorite. Again – go for the full paid version and don’t try to cut corners on freemium or freeware versions. An ounce of prevention is worth a pound of cure.  You need protection that is going to detect phishing from spam, detect unsafe websites and web browser protection.
  2. Put strong back up procedures in place– you should have back ups in place with a return point objective that you can live with. That means that you should have back ups both onsite on a device and in the cloud. Both of the back ups should be constantly tested for verification and the process should be monitored. When this is successfully in place, in case of an outbreak, you can restore to the last back up that was unaffected. Please note: tape drives, USB sticks, and removable hard drives are not adequate for business applications. You need a proper belt and suspenders- a properly sized on premise device that is backed up to the cloud.
  3. Make sure that you are updating your operating system and plug ins regularly – the current round of ransomware is exploiting unpatched and un-updated Windows vulnerabilities. We update our clients with whitelisted patches and updates from Microsoft. Make sure that you are constantly updating your operating system. Make sure that you are scheduling your updates properly- for all of your computers and all of your devices. Make sure you update all of your computers- even those that you may use less frequently. For example, we use micro pc’s in our conference room- for use with our large screen monitors. All of those units must be updated regularly.
  4. Make sure that your firewall is regularly updated and maintained– your firewall should be under contract and updated with the very latest definitions. Your firewall is all that stands between you and the virus filled Internet. We recommend Watchguard because it is constantly being updated and maintained – and it includes best of breed components that would be too expensive to buy separately bundled in.
  5. Disable autorun- make sure that you disable autorun for everyone!!Yes, autorun is useful. Yes, it is also used by viruses and malware to propagate itself throughout a network. In these dangerous times, disable it.
  6. Stop making everyone an Admin!! – administrators should be admins. However, if you give everyone admin rights, you open yourself up to more damage. User should be users and admins should be admins. Period.
  7. Enforce secure passwords– believe it or not, people use stupid passwords. Enough with stupid. If you want to get infected, use a simple password. If you don’t use a secure password (strong with characters, alphanumeric and symbols). Better yet, have your users get a password manager app.
  8. When relevant, encourage the use of two factor authorization– if you have compliance requirements (HIPAA or PCI) definitely use two factor authorization.
  9. Disable RDP– remote desktop protocol is used by all sorts of viruses and malware to gain access. If you don’t need it or don’t know what it is, disable it.
  10. Educate EVERYBODY– even if your office is a handful of people- but especially if you have less sophisticated users- education of the threat is important. Your staff should know what phishing, spear phishing and how to recognize and avoid suspicious emails. Incorporate this into your onboarding of new employees or have a meeting about this. If you would like a recommendation for videos, send me an email and I will send you a recommended list. Along with that, add pertinent sections to your employee manual about bringing your own device onto the network, using “free”USB drives, and clicking on links in emails.

Like I said, this is by no means a comprehensive list. I have learned Mark Twain may have had the last word. “It’s not what you know that gets you in trouble, it’s what you know for sure that just ain’t so”. The world of viruses and malware is changing. Yesterday’s method may be overcome in an instant and you have to keep on top of it. If you need help- just let me know!

 

AAEH Threat Alert

The following information is from the US Computer Emergency Readiness Team (US CERT) part of the Department of Homeland Security. The full text can be found here.

Network Security

AAEH

Original release date: April 09, 2015
Systems Affected
  • Microsoft Windows 95, 98, Me, 2000, XP, Vista, 7, and 8
  • Microsoft Server 2003, Server 2008, Server 2008 R2, and Server 2012

Overview

AAEH is a family of polymorphic downloaders created with the primary purpose of downloading other malware, including password stealers, rootkits, fake antivirus, and ransomware.

The United States Department of Homeland Security (DHS), in collaboration with Europol, the Federal Bureau of Investigation (FBI) and the Department of Justice (DOJ), released this Technical Alert to provide further information about the AAEH botnet, along with prevention and mitigation recommendations.

Description

AAEH is often propagated across networks, removable drives (USB/CD/DVD), and through ZIP and RAR archive files. Also known as VObfus, VBObfus, Beebone or Changeup, the polymorphic malware has the ability to change its form with every infection. AAEH is a polymorphic downloader with more than 2 million unique samples. Once installed, it morphs every few hours and rapidly spreads across the network.  AAEH has been used to download other malware families, such as Zeus, Cryptolocker, ZeroAccess, and Cutwail.

Impact

A system infected with AAEH may be employed to distribute malicious software, harvest users’ credentials for online services, including banking services, and extort money from users by encrypting key files and then demanding payment in order to return the files to a readable state. AAEH is capable of defeating anti-virus products by blocking connections to IP addresses associated with Internet security companies and by preventing anti-virus tools from running on infected machines.

Solution

Users are recommended to take the following actions to remediate AAEH infections:

  • Use and maintain anti-virus software – Anti-virus software recognizes and protects your computer against most known viruses. It is important to keep your anti-virus software up-to-date (see Understanding Anti-Virus Software for more information).
  • Change your passwords – Your original passwords may have been compromised during the infection, so you should change them (see Choosing and Protecting Passwords for more information).
  • Keep your operating system and application software up-to-date – Install software patches so that attackers can’t take advantage of known problems or vulnerabilities. Many operating systems offer automatic updates. If this option is available, you should enable it (see Understanding Patches for more information).
  • Use anti-malware tools – Using a legitimate program that identifies and removes malware can help eliminate an infection.

Users can consider employing a remediation tool (examples below) that will help with the removal of AAEH from your system.

Note: AAEH blocks AV domain names thereby preventing infected users from being able to download remediation tools directly from an AV company. The links below will take you to the tools at the respective AV sites. In the event that the tools cannot be accessed or downloaded from the vendor site, the tools are accessible from Shadowserver (http://aaeh.shadowserver.org).

The below are examples only and do not constitute an exhaustive list. The U.S. Government does not endorse or support any particular product or vendor.

References

Revisions

  • April 9, 2015: Initial Release

New Threat: CryptoLocker Ransomware Virus

This is a Reposting: Important from US CERT

 

National Cyber Awareness System:

11/05/2013 10:58 AM EST
Original release date: November 05, 2013 | Last revised: November 06, 2013

Systems Affected

Microsoft Windows systems running Windows 7, Vista, and XP operating systems

Overview

US-CERT is aware of a malware campaign that surfaced in 2013 and is associated with an increasing number of ransomware infections. CryptoLocker is a new variant of ransomware that restricts access to infected computers and demands the victim provide a payment to the attackers in order to decrypt and recover their files. As of this time, the primary means of infection appears to be phishing emails containing malicious attachments.

Description

CryptoLocker appears to have been spreading through fake emails designed to mimic the look of legitimate businesses and through phony FedEx and UPS tracking notices.  In addition, there have been reports that some victims saw the malware appear following after a previous infection from one of several botnets frequently leveraged in the cyber-criminal underground.

Impact

The malware has the ability to find and encrypt files located within shared network drives, USB drives, external hard drives, network file shares and even some cloud storage drives.  If one computer on a network becomes infected, mapped network drives could also become infected. CryptoLocker then connects to the attackers’ command and control (C2) server to deposit the asymmetric private encryption key out of the victim’s reach.

Victim files are encrypted using asymmetric encryption. Asymmetric encryption uses two different keys for encrypting and decrypting messages. Asymmetric encryption is a more secure form of encryption as only one party is aware of the private key, while both sides know the public key.

While victims are told they have three days to pay the attacker through a third-party payment method (MoneyPak, Bitcoin), some victims have claimed online that they paid the attackers and did not receive the promised decryption key.  US-CERT and DHS encourage users and administrators experiencing a ransomware infection NOT to respond to extortion attempts by attempting payment and instead to report the incident to the FBI at the Internet Crime Complaint Center (IC3).

Solution

Prevention

US-CERT recommends users and administrators take the following preventative measures to protect their computer networks from a CryptoLocker infection:

  • Do not follow unsolicited web links in email messages or submit any information to webpages in links
  • Use caution when opening email attachments. Refer to the Security Tip Using Caution with Email Attachmentsfor more information on safely handling email attachments
  • Maintain up-to-date anti-virus software
  • Perform regular backups of all systems to limit the impact of data and/or system loss
  • Apply changes to your Intrusion Detection/Prevention Systems and Firewalls to detect any known malicious activity
  • Secure open-share drives by only allowing connections from authorized users
  • Keep your operating system and software up-to-date with the latest patches
  • Refer to the Recognizing and Avoiding Email Scams (pdf) document for more information on avoiding email scams
  • Refer to the Security Tip Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks

Mitigation

US-CERT suggests the following possible mitigation steps that users and administrators can implement, if you believe your computer has been infected with CryptoLocker malware:

  • Immediately disconnect the infected system from the wireless or wired network. This may prevent the malware from further encrypting any more files on the network
  • Users who are infected should change all passwords AFTER removing the malware from their system
  • Users who are infected with the malware should consult with a reputable security expert to assist in removing the malware, or users can retrieve encrypted files by the following methods:
    • Restore from backup,
    • Restore from a shadow copy or
    • Perform a system restore.

References

Revision History