Category Archives: Advice for SMEs

Top secret information about Australia’s military hacked – SME’s overstretched with Cyber Security Frameworks

15 October 2017

Lisa Martins report Top secret information about Australias military hacked, published on October 12th, 2017 at news.com.au, about a one year old attack on an Australian defense contractor is another example that small businesses are technically and organizationally overstretched with the challenges of cyber security.

The best approach for SMEs would be to set up a cyber security framework like the NIST Cyber Security Framework or an ISO 27001 based framework. But the effort to do this is for small businesses just too high.

For SMEs to stay ahead of the cyber security curve a light version of such frameworks is required, with focus put on actively managing the risk.

The Strategies to Mitigate Cyber Security Incidents of the Australian Signals Directorate (ASD) puts focus on the basics. If carefully implemented and regularly assessed, the security level goes up and this kind of attacks are no longer possible. Even large businesses can raise their security level when implementing the ASDs recommendations.

But when it comes to critical infrastructures a full implementation of a cyber security frameworks is the only way to survive in the long-term. By the way, the first task in the NIST CSF core is asset management…

Have a great week.

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Critical vulnerabilities require immediate action – How to prevent Equifax like attacks

23 September 2017

Critical Vulnerabilities are

  • exploitable from the network (Access Vector: Network),
  • require only low or medium skills to exploit (Access Complexity: Low or Medium),
  • require no authentication (Authentication: None),
  • cause great damage (Severity: High), and
  • allow remote attackers to execute arbitrary code on the victims’ computer

Among the vulnerabilities with CVSS vector (AV:N/AC:L/Au:N) or (AV:N/AC:M/Au:N) which cause great damage the last property makes the difference.

The infographic below shows that the number of critical vulnerabilities (320) is very small compared to the total number of vulnerabilities in 2016.

Critical Vulnerabilities 2016

Critical vulnerabilities 2016. Click to enlarge.

Nevertheless, immediate action is required because the reach of attacks is technically unlimited if critical vulnerabilities can be exploited.

Once an attacker has exploited a critical vulnerability in the DMZ he is able to execute arbitrary code on this computer. With this, he can probe the network for other computers with critical vulnerabilities or leverage Windows built-in weaknesses, configuration issues, and tools to explore the network until he finally gets to a computer which has a connection across a firewall to the company network.

Both, NotPetya and WannaCry exploited critical vulnerabilities. While WannaCry was just annoying, NotPetya caused multi-million dollar damage in companies across the world.

Mitigation

The TEAM approach for handling risks shows the direction for dealing with critical vulnerabilities.

Transfer: No insurer will take the risk because in the case of a critical vulnerability on a server in the DMZ both the probability of occurrence and the impact are high.

Eliminate: Is not possible, because this will result in loss of business.

Accept: No option because the probability of occurrence and the impact are high.

Mitigate: Patching is the only possible response in this case. Isolation of the system from the network will result in loss of business.

Urgency

Under normal conditions, patches are available at the time of disclosure.

Rule: Critical vulnerabilities should be patched faster than exploits show up on the market.

With this, immediate action is required because very often exploits are available yet at the time of disclosure. In addition, we cannot expect that only ethical hackers publish vulnerabilities.

Equifax

Critical Vulnerabilities Mitigation Process

Critical vulnerabilities mitigation process.

In the Equifax attack the critical vulnerability CVE-2017-5638 in the Apache Struts framework was used. A patch was available at the time of disclosure but apparently not applied.

Patching the Apache Struts framework is a challenging job.

Firstly, it is a challenge to identify the systems with the vulnerable framework installed.

Secondly, patches must be carefully tested prior implementation to avoid business loss.

Finally, the patches must be implemented manually because automated patch management is not available.

Thus, an up-to-date asset repository, a current QA system, and actual automated test routines are required to get the job done in the required short time frame.

To be honest, the Equifax attack remains a mystery for me. The IT shop of a billion dollar company should be able to deal with critical vulnerabilities in the required short time. Perhaps someone simply underestimated the risk.

For more details on the Equifax attack see Steven Bellovin’s post Preliminary Thoughts on the Equifax Hack published at CircleID.

Have a great weekend.

German firms lost millions of euros in ‘CEO Fraud’ scam: BSI

23 July 2017

The report ‘German firms lost millions of euros in ‘CEO Fraud’ scam: BSI’ published in the Reuters Technology News on 10 July 2017 makes me really worry. Whaling, a special form of spear phishing aimed on corporate executives, is not new at all. For some samples see this slide show on CIO.com.

It appears to me that in Germany the first line of defense, the employees, are not adequately prepared in the detection and the correct handling of phishing attacks, even though anti-phishing training is the most effective and cost efficient defensive measure in the fight against all kinds of phishing.

In addition, some rules are helpful and should be communicated to all employees:

  1. Users should never act on a business request from a company executive if the email is not signed with a company owned and valid email certificate.
  2. Users should never trust an email of a business partner if it is not signed with the partners valid email certificate.

Technical implementation is very easy, thus even SMB can use email signing in daily communication.

Have a great week.

Some thoughts on “Ransomware a real risk for SCADA networks”

5 June 2017

By now the ‘Air gapping’ myth should be expunged from every ICS/SCADA manager on earth.” I really like this statement from Daniel Cohen-Sason, published on 23 May 2017 in the CYBERBIT blog.

From my point of view, the ‘Air Gap’ era ended with the introduction of portable engineering stations about 30 years ago.

Modern OT networks are often designed on the basis of the ISA 95 Standard with network zones and security devices, e.g. firewalls, to control the communications flow between the process control and SCADA systems across the zones. Modern production requires a lot of Machine-to-Machine (M2M) communication between the production networks zones and between the production network and the business network. Besides this M2M communication Human-to-Machine (H2M) communication is required, e.g. for operator access from the business network and for remote maintenance.

For M2M and H2M interaction communication channels must be opened on the firewalls. With this, there is always a chance that malware can spread across such required connections. Furthermore, cyber attackers can gain access, e.g. through remotely exploitable vulnerabilities, after they hijacked a M2M communications endpoint in the business network. We dealt with this very effectively in the past 20 years.

Many of the required connections use the SMB protocol for exchange of data. That’s no problem per se. The problem is, that we still use Windows 7 and Windows Server 2008 in the manufacturing industry which cannot work with the latest versions of the SMB protocol for data exchange.

Since WannaCry exploited a vulnerability in SMB version 1.0, it was only a matter of time before WannaCry would find its way across a required connection from the business network to the production network.

How to deal with the problem?

  • Priority patching.

The systems at the border between the business network and the production network must me patched with highest priority. Although this is somewhat tricky to achieve in WSUS, it’s worth to deal with this WSUS feature. In addition to the operating system components, all application components must be patched as well. The same applies to Linux based systems.

  • Deactivating SMB.

Is a great means in the case of an emergency, and part of a long-term data exchange strategy.

  • Set up asset and vulnerability management.

At least all systems at the endpoints of required M2M and H2M connections must be included. This enables you to evaluate the scale of the problem in the case of a new vulnerability.

  • Faster innovation cycles.

At least for the systems at the perimeter of the production network we must allow for shorter innovation cycles. With Windows 8, Windows 10, and Windows Server 2012, new versions of the SMB protocol are used which are not affected by WannaCry. Don’t forget to deactivate the SMB V1.0 compatibility in the this versions.

This includes the technology used for data exchange. For example, the widely used Robocopy fosters the spreading of WannaCry because it is based on the SMB protocol.

  • Increase the level of isolation.

Start with challenging the required M2M and H2M connections. Eliminate every connection without a business purpose. For the remaining, check whether the best available security technology is used.

Take care!

Ransomware for Industrial Control System – Digital Carelessness

19 March 2017

Ransomware for Industrial Control Systems (ICS) is a scaring idea. The research paper ‘Out of Control: Ransomware for Industrial Control System‘ by David Formby, Srikar Durbha and Raheem Beyah from the Georgia Institute of Technology is really worth reading.

The researchers study several attack vectors and run a proof of concept (POC). In addition, they give some hints for mitigation of this new risk in the ICS / SCADA domain.

In the simplest case, if the PLC is connected to the internet, the cyber-criminal can attack the PLC directly. A more dangerous, but also very promising way is to start an attack on a workstation located in the corporate network and use this system as base camp for the access to the production network.

In the past weeks I prepared a speech for a workshop about “Safety and security in plant safety”. In the IIoT, the digital world acts upon the physical world. With this, flaws in the IIoT software may create a safety problem. For example, if a PLC or other SCADA components are attached to the internet, cyber criminals can exploit such flaws and compromise the integrity of the systems or implement ransomware on the systems. In the worst case, if e.g. the SCADA system controls a critical infrastructure like a power grid, this may result in a blackout. And operators of critical infrastructures will pay definitely any ransom to avoid a blackout.

The attack vectors described above are the native way for accessing industrial facilities and critical infrastructures. Besides the PLC, lots of other components like switches or HMI panels are connected more or less intentionally to the internet today. My colleague Christoph Thust from Evonik calls this the Digital Carelessness.

A plain SHODAN search for ‘SCALANCE‘ results in 213 hits. These network switches are more or less exposed to the internet. If a cyber attacker can hijack such a switch, he gains full control of the production network.

Shodan Scalance Search

Shodan Scalance Search. Click to enlarge.

A search for ‘SIMATIC HMI‘ results in 103 hits. This HMI panels are directly attached to the internet, lots of them can be viewed with WinVNC, some of them can be fully operated by EVERYONE.

Shodan Search HMI

Shodan Search HMI. Click to enlarge.

And, above all, HMI panels attached to the internet can be used as base camp for an attacker’s lateral movement in the production network.

Although ransomware is a really big issue today, the effort to rollout ransomware in a SCADA environment is high compared to the effort of plain attacks to unsecured SCADA system components.

The good news is, that the vendors of SCADA components already offer the elementary technology and strategies for their secure operation. But improvement of the basic security technologies is of crucial need for efficient use in the production domain.

The bad news is, that neither the engineering service providers nor the plant operators are fully aware of cyber-threats and their impact on plant operations and safety. The above examples make clear that the mitigation measures and defense strategies provided by the technology vendors are not followed.

From my point of view we need to start early in the construction process with considerations of cyber security. Security gates must be added to each construction phase. And during handover to the operator, a final pen test must be performed. As soon as Security by Design becomes an integral part of the Industrial Plant Life Cycle, the era of digital carelessness will end.

Have a good weekend.

Rethinking the Patch Strategy in the ICS Domain

5 February 2017

In the past weeks I reviewed several drafts on Industrial Control System (ICS) security. Although of limited value in the ICS Domain, patching and malware protection are key issues of all drafts.

Especially the patch process, which works moderately satisfying in the Office-IT domain, cannot be directly applied to ICS systems because ICS systems cannot be just rebooted to apply the patch.

Industrial control system patch cycle

Industrial control system patch cycle

To reboot an ICS system a shutdown of the process is required. In the worst case, the operators have to wait several weeks or months for the next scheduled plant maintenance to implement the patch and to reboot the ICS. During this time the ICS is more vulnerable against the threats mitigated by the patch.

With this, we have to design and operate our ICS systems and networks such, that they are resilient against cyber-attacks during the time until the next scheduled maintenance.

The following are examples of technical measures:

  • Isolation of ICS and SCADA systems in secured network zones inside the production network and strict flow control across security devices between the zones are basic design principles for creating robust systems.
  • A secure remote maintenance solution which is completely under control of the plant operators, ideally a rendezvous solution to keep the external service provider in the DMZ.
  • A secure and controlled remote access solution for plant operators.
  • Strict Network Access Control in the entire production network to increase resilience against attackers from internal.
  • No Internet access and personal email in the entire production network. This is a quick win! The same holds for the deactivation of USB disk devices.

Have a good weekend.

Whaling emerges as major cybersecurity threat

3 December 2016

Whaling is a type of cyber fraud that targets mainly corporate executives. It is very closely related with phishing, thus not new. For a superb collection of examples see this slide show published on CIO.com.

As always, the combination of People, Process and Technology measures (PPT approach) is the best way to combat whaling:

People. The most effective way to deal with whaling is security awareness training. Include some whaling attacks in your anti-phishing training to raise awareness.

Processes. Enhance your information handling policy (IHP) or office manual. Add rules for the compliant handling of business requests by email:

  1. Users should never act on a business request from a company executive if the email is not signed with a company owned and valid email certificate.
  2. Never trust an email of a business partner when it is not signed with the partners valid email certificate.

Communicate the IHP to all users and train them in use and handling of email certificates.

Technology. Configure your email system such that all mails to external partners and at least all emails from company executives are signed with a valid email certificate.

With this, the risk of getting the victim of a whaling attack is greatly reduced.

Have a good weekend.