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Three myths about Ransomware

Three Myths about Ransomware

Ransomware is a popular weapon for the modern attacker with >50% of the 330,000+ attacks in 3Q15 targeted against US companies. No industry is immune to these attacks, which if successful are a blot on financial statements of the targeted companies. Despite their success, ransomware attacks are not sophisticated, exploit traditional infection vectors and are not stealthy. The success of such attacks reveal poor endpoint protection planning and strategy, which are observed at companies of every size and every vertical. This leads to most organizations reacting to such infections rather than planning against them, which is expensive in staff hours and of course hurtful to reputation.

A misunderstanding of ransomware, how it works and how the infection can be prevented are common. Here are three common misconceptions:

Myth #1: Ransomware is a zero-day attack

In fact, exploiting a zero-day vulnerability is an expensive proposition for a malicious actor. In reality, most malware target vulnerabilities, which while well-documented and easily remediated, remain unpatched. Therefore, a systematic schedule of patching and endpoint system updates within 30 days of becoming available is the most effective available way to minimize the threat of ransomware, and indeed most “targeted” attacks.

Myth #2: Anti-virus & perimeter solutions are sufficient protection

Signature-based protection has been widely used for 20+ years and is a necessary and effective protection mechanism. However, this approach is well known and easily evaded by attackers. In addition to signature-based anti-virus solutions, it is necessary to consider endpoint detection and response solutions supported by monitoring and analytics. Many ransomware attacks are successful because attackers breach perimeter security solutions and web-facing applications. Most networks are flat, making them easy to traverse. Segmenting assets into trust zones and enforcing traffic flow rules is the way to go.

Myth #3: IT Admins always follow best practices

When administrator accounts are not monitored at all, it exposes such super powers to hacker opportunism. Admin workstations with drive mappings and often used (and sadly common) administrator passwords to critical servers are a high priority target. Best practice prescribes monitoring administrator accounts for unauthorized use, access and behaviors.

Recognize that ransomware itself isn’t much different than the malware of the past. Ransomware enters the organization the same way as other malware, propagates the same way and leverages known vulnerabilities in the same way. Thus the good news is that ransomware can also be defended in the same way as malware.

WannaCry: What to do if you can’t update Microsoft Windows

By A.N. Ananth

A global pandemic of ransomware hit Windows based systems in 150 countries in a matter of hours. The root cause was traced to a vulnerability corrected by Microsoft for supported platforms (Win 7, 8.1 and higher) in March 2017, about 55 days before the malware was widespread. Detailed explanations and mitigation steps are described here. The first step to mitigation is to apply the update from Microsoft. A version for XP and 2003 was also released by Microsoft on Friday May 12, 2017.

But what if you did not apply the update because you just cannot do so? This is often the case in Industrial Control Systems (ICS), which comprise Operational Technology (OT) systems built on the same platforms (Windows XP, 7) that are susceptible to this vulnerability, but the patch/backup strategy recommended for traditional desktops just simply does not apply.

There are reports of several manufacturers that have apparently stopped work at plants because of WannaCry infestations of control systems, including automobile manufacturers like Renault, Dacia, and Nissan. There are many valid reasons:

  • The earlier versions of Microsoft software used in ICS aren’t just off-the-shelf versions of Windows, but they’re Windows as mediated by industrial control system vendors like Honeywell, Siemens and the like. They don’t use off-the-shelf Windows. Applying updates requires testing to ensure the ICS system is not going to be disrupted.
  • ICS system owners abhor downtime. It is very expensive to shut down a manufacturing line or an airport runway, and not possible to shut down the International Space Station.
  • ICS system owners often cite the “air gap”. But that’s a myth that has been exploded often.

As a start, ICS-CERT has published an advisory which provides this guidance:

  • Disable SMBv1 on every system connected to the network.
    • Information on how to disable SMBv1 is available here.
    • While many modern devices will operate correctly without SMBv1, some older devices may experience communication or file/device access disruptions.
  • Block port 445 (Samba).
    • This may cause disruptions on systems that require port 445.
  • Review network traffic to confirm that there is no unexpected SMBv1 network traffic. The following links provide information and tools for detecting SMBv1 network traffic and Microsoft’s MS17-010 patch:
  • Vulnerable embedded systems that cannot be patched should be isolated or protected from potential network exploitation.

If you need help and aren’t currently a customer, the same SIEM technology that detected WannaCry for our SIEMphonic Enterprise Edition customers can protect your systems as well. Our solution is designed to protect endpoints from unknown processes, like ransomware, and has been proven effective in tens of millions of installations. Find out more here.

WannaCry: Nuisance or catastrophe? What to expect next?

As we come to the one week point of the global pandemic of ransomware called WannaCry, it seems that while the infection gained worldwide (and unprecedented) news coverage, it has been more of a global nuisance than a global catastrophe. Some interesting points to note:

  • The most affected systems were un-patched Windows 7 and 2008 — not XP as thought earlier. This clearly points to patching cycle. It also validates the approach taken by Microsoft in Windows 10 to force Windows updates for consumers and small business. There was a lot of rage against the machine at the time, but in retrospect, can we agree that it was the right design choice?
  • The distribution method was not a phishing email, rather it seems the malware authors spread by scanning for networks that did not block port 445, which is used by the SMB protocol. It’s high time to correct this mis-configuration. Here is how to do it.
  • It may be that in the eyes of some users, this is another case of the security industry crying “wolf” again, thereby contributing to the numbness to such outbreaks.

What can we expect going forward?

  • As usual, criminals will be quick to take advantage of the attendant fear by pitching phony schemes to “protect” those that are worried they may be, or may become, victims.
  • There will be copycat malware. The distribution by worm (instead of phishing) makes network hygiene even more important.
  • Leaks will increase. Both Wikileaks and Shadow Brokers received tremendous publicity, and given the commercial nature of the latter, they will try and leverage this notoriety.
  • Patch hygiene may improve for a short period in businesses. This is similar to a driver slowing down after observing someone else pulled over by the police. The effects are only temporary though, sad to say.
  • Collaboration across the industry was a big part of blunting the damage. It looks set to continue, which is an incredibly good thing.

Do hackers prefer attacking over the weekend?

The recent WannaCry attack started on a Friday and it was feared that the results would be far more severe on Monday, as workers trickled back from the weekend. The fraudulent wires from Bangladesh Bank that resulted in $81M lost also happened on a Friday. A detailed account of how this weekend timing allowed hackers to get away a large sum (rerouted to the Philippines) with is described in this Reuters investigation.

Attribution in each case has veered towards a state-sponsored attacker that is interested in financial gain. The finger of suspicion points to North Korea in both cases. Lamont Siller, an FBI officer in the Philippines in a speech said, “We all know the Bangladesh Bank heist, this is just one example of a state-sponsored attack that was done on the banking sector.” Symantec in a blog update reported “that its researchers found hacking tools that are ‘exclusively used by Lazarus’ on machines infected with early versions of WanaCryptor, aka WannaCry.” Lazarus is thought to have originated in North Korea.

All righty then, 1) attacks are state sponsored, persistent and advanced, and 2) timed for non-working hours. So are you ready to defend against such attackers? You know, you are not alone. EventTracker’s SIEMphonic service blends award winning SIEM technology with a 24/7 iSOC to give you the cover you need at a price that won’t break the bank.

Want to know more? Here is how we caught WannaCry and what we are doing about it for our customers.

WannaCry at Industrial Control Systems

WannCry-Control-Systems

A global pandemic of ransomware hit Windows based systems in 150 countries in a matter of hours. The root cause was traced to a vulnerability corrected by Microsoft for supported platforms (Win 7, 8.1 and higher) in March 2017, about 55 days before the malware was widespread. Detailed explanations and mitigation steps are described here. The first step to mitigation is to apply the update from Microsoft. A version for XP and 2003 was also released by Microsoft on Friday May 12, 2017.

But what if you did not apply the update because you just cannot do so? This is often the case in Industrial Control Systems (ICS), which comprise Operational Technology (OT) systems built on the same platforms (Windows XP, 7) that are susceptible to this vulnerability, but the patch/backup strategy recommended for traditional desktops just simply does not apply.

There are reports of several manufacturers that have apparently stopped work at plants because of WannaCry infestations of control systems, including automobile manufacturers like Renault, Dacia, and Nissan. There are many valid reasons:

  • The earlier versions of Microsoft software used in ICS aren’t just off-the-shelf versions of Windows, but they’re Windows as mediated by industrial control system vendors like Honeywell, Siemens and the like. They don’t use off-the-shelf Windows. Applying updates requires testing to ensure the ICS system is not going to be disrupted.
  • ICS system owners abhor downtime. It is very expensive to shut down a manufacturing line or an airport runway, and not possible to shut down the International Space Station.
  • ICS system owners often cite the “air gap”. But that’s a myth that has been exploded often.

As a start, ICS-CERT has published an advisory which provides this guidance:

  • Disable SMBv1 on every system connected to the network.
    • Information on how to disable SMBv1 is available here.
    • While many modern devices will operate correctly without SMBv1, some older devices may experience communication or file/device access disruptions.
  • Block port 445 (Samba).
    • This may cause disruptions on systems that require port 445.
  • Review network traffic to confirm that there is no unexpected SMBv1 network traffic. The following links provide information and tools for detecting SMBv1 network traffic and Microsoft’s MS17-010 patch:
  • Vulnerable embedded systems that cannot be patched should be isolated or protected from potential network exploitation.

WannaCry: Fraud follows fear

After the global pandemic of the WannaCry ransomware attack this past weekend, it’s entirely predictable that fraudsters would follow. After every major attack or vulnerability disclosure, criminals are quick to take advantage of the attendant fear by pitching phony schemes to “protect” those that are worried they may be, or may become, victims.

This has indeed occurred already in the wake of WannaCrypt. Various third-party mobile app stores are offering protection from the ransomware, but those protective apps are for the most part bogus, and commonly infested with adware. So, steer clear of apps promising protection, and instead patch and update your systems.

Spam emails notifying you that your machine is infected with WannaCry (see picture below) are also making the rounds.

WannaCry Ransomware

Here’s some guidance to be safe from these attempts:

  • Apply the Microsoft patch for the MS17-010 SMB vulnerability dated March 14, 2017.
  • Perform a detailed vulnerability scan of all systems on your network and apply missing patches ASAP.
  • Limit traffic from/to ports 139 and 445 to internal network only. Monitor traffic to these ports for out-of-ordinary behavior.
  • Enable strong spam filters to prevent phishing e-mails from reaching the end users and authenticate in-bound e-mail using technologies like Sender Policy Framework (SPF), Domain Message Authentication Reporting and Conformance (DMARC), and DomainKeys Identified Mail (DKIM) to prevent e-mail spoofing.
  • Scan all incoming and outgoing e-mails to detect threats and filter executable files from reaching the end users.
  • Ensure anti-virus and anti-malware solutions are set to automatically conduct regular scans.
  • Manage the use of privileged accounts. Implement the principle of least privilege. No users should be assigned administrative access unless absolutely needed. Those with a need for administrator accounts should only use them when necessary.
  • Configure access controls including file, directory and network share permissions with least privilege in mind. If a user only needs to read specific files, they should not have write access to those files, directories or shares.
  • Disable macro scripts from Microsoft Office files transmitted via e-mail. Consider using Office Viewer software to open Microsoft Office files transmitted via e-mail instead of full Office suite applications.

Feeling overwhelmed? Don’t despair. Expert help available here.

WannaCry: What it is and what to do about it

What happened

For those of us in the IT Security profession, Friday May 12 was Black Friday. Networks in healthcare and critical infrastructure across at least 99 countries have been infected by the WannaCry ransomware worm, aka WanaCrypt, WannaCrypt or Wcry. The bulk of infections were reported in Russia, Taiwan and Spain.

First observed targeting UK hospitals and Spanish banks, big companies like Telefónica, Vodafone and FedEx had some of their systems infected with the threat that also hit rail stations and universities. The Spanish CERT issued an alert warning the organizations and confirming that the malware was rapidly spreading.

Is it over? Will it happen again?

A sample of malware was reverse engineered and found to contain a “kill switch“. The malware tries to resolve a particular domain name and if it exists, it self destructs. This domain has been registered and so, if you are infected and this particular strain is able to successfully resolve that domain name using your internet connection and DNS settings, then it will apparently terminate itself. Obviously hope is not a strategy and assuming that we don’t have to do anything now is a big mistake. It is inevitable that a new strain which won’t have any such kill switch will emerge. Accordingly, it is imperative to strengthen defenses.

How it spreads

Initial infection is possibly via phishing email. CERT also reported that the hacker or hacking group behind the WannaCry campaign is gaining access to enterprise servers either through Remote Desktop Protocol (RDP) compromise. Once the infection has taken root, it spreads across the network looking for new victims using the Server Message Block (SMB) protocol. The ransomware uses the Microsoft vulnerability MS17-10[1]. This vulnerability was used by ETERNALBLUE, an exploit that was developed by the NSA and released to the public by the Shadow Brokers, a hacker group on April 14, 2017. Microsoft released a patch for this vulnerability on March 14, one month before the release of the exploit.

What it does

Once the infection is on the machine, it encrypts files and shows a ransom note asking for $300 or $600 worth of bitcoin.

Technical details

As described by CERT, the WannaCry ransomware is a loader that contains an AES-encrypted DLL. During runtime, the loader writes a file to disk named “t.wry”. The malware then uses an embedded 128-bit key to decrypt this file. This DLL, which is then loaded into the parent process, is the actual Wanna Cry Ransomware responsible for encrypting the user’s files. Using this cryptographic loading method, the WannaCry DLL is never directly exposed on disk and not vulnerable to antivirus software scans.

The newly loaded DLL immediately begins encrypting files on the victim’s system and encrypts the user’s files with 128-bit AES. A random key is generated for the encryption of each file.

The malware also attempts to access the IPC$ shares and SMB resources the victim system has access to. This access permits the malware to spread itself laterally on a compromised network. However, the malware never attempts to attain a password from the victim’s account in order to access the IPC$ share.

This malware is designed to spread laterally on a network by gaining unauthorized access to the IPC$ share on network resources on the network on which it is operating.

What steps has EventTracker SIEMphonic taken?

  1. Closely monitoring announcements and details provided by industry experts including US CERT, SANS, Microsoft, etc.
  2. Reviewed the latest vulnerability scan results from your network (if subscribed to ETVAS service) for vulnerable machines. ETVAS service subscribers who would like us to scan your network again can request us at ecc@eventtracker.com and we will perform a scan at your convenience.
  3. Updated the Active Watch List in your instance of EventTracker with the latest Indicators of Compromise (IOCs). This includes MD5 hashes of the malware variants, IP addresses of WannaCry C&C servers and domain names used by the malware
  4. Added an alert if we see any logs containing the domain name iuqerfsodp9ifjaposdfjhgosurijfaewrwergwea.com which is used by WannaCry
  5. Watching Change Audit snapshots in your network for changes to registry (RunOnce) and for files with extension .wncry
  6. Updated ETIDS with snort signatures as described by the SANS Internet Storm Center
  7. Performing log searches using known IOCs

Recommended steps for prevention

  • Apply the Microsoft patch for the MS17-010 SMB vulnerability dated March 14, 2017.
  • Perform a detailed vulnerability scan of all systems on your network and apply missing patches ASAP.
  • Limit traffic from/to ports 139 and 445 to internal network only. Monitor traffic to these ports for out of ordinary behavior.
  • Enable strong spam filters to prevent phishing e-mails from reaching the end users and authenticate in-bound e-mail using technologies like Sender Policy Framework (SPF), Domain Message Authentication Reporting and Conformance (DMARC), and DomainKeys Identified Mail (DKIM) to prevent e-mail spoofing.
  • Scan all incoming and outgoing e-mails to detect threats and filter executable files from reaching the end users.
  • Ensure anti-virus and anti-malware solutions are set to automatically conduct regular scans.
  • Manage the use of privileged accounts. Implement the principle of least privilege. No users should be assigned administrative access unless absolutely needed. Those with a need for administrator accounts should only use them when necessary.
  • Configure access controls including file, directory, and network share permissions with least privilege in mind. If a user only needs to read specific files, they should not have write access to those files, directories, or shares.
  • Disable macro scripts from Microsoft Office files transmitted via e-mail. Consider using Office Viewer software to open Microsoft Office files transmitted via e-mail instead of full Office suite applications.

How EventTracker protected customers

See the details in the Catch of the Day

Challenges with Threat Intelligence or why a Honeynet is a good idea

Shared threat intelligence is an attractive concept. The good guys share experiences about what the bad guys are doing thereby blunting attacks. This includes public-private partnerships like InfraGard, a partnership between the FBI and the private sector dedicated to sharing information and intelligence to prevent hostile acts against the U.S.

The analogy can be made to casinos that share information with each other about cheaters and their characteristics via the Gaming Board or the Griffin Book. If you share the intelligence then everybody but the cheater wins. So why not the same for cyber security?

For one thing, you are dealing with anonymous adversaries capable of rapid change, unlike the casino analogy where facial recognition can identify an individual even if their appearance is modified. Also, the behavior of the casino cheat tends to be similar (for example sit at the craps table or counting cards at blackjack as in Rain Man). In the cybersecurity world, all the defender has to go on is the type of attack (malware, phishing, ransomware), an IP range, and possibly a domain name. So the indicators of compromise (IOCs) that can be shared are file hashes, domain names, and sender email domains-all multiplying and morphing at digital speed. The IOCs are very hard to share globally at the scale and speed of the internet.

In addition, when the good guys share the IOCs, they do so in ways that are visible to bad guys as well (e.g., upload suspect files to Virus Total). This is leveraged by the bad guys to know the progress of the defenders and therefore adapt their attack.

So what now?

One solution is to implement local threat intelligence with a honeynet, a cyber-defense product that thwarts attempts by attackers to gain information about a private network. Comprised of
multiple virtualized decoys strategically scattered throughout the network to lure bad actors, honeynets can provide intelligence about malicious activity against the network. This solution is effective in identify bad actors including insiders, by their behavior, in your neighborhood. This blog describes the how they differ from Threat Intelligence.