Monday 22 July 2019

Configuration Reviews: Ensuring Security in the Cloud

Written by Charlie Clark

What is a configuration review?

As businesses increasingly move their critical business processes into cloud services, ensuring the security of those services is ever more important. It can be easy to brush off the responsibility of the services’ security onto the provider, but this isn’t the best idea. While the provider is responsible for the security of the platform, the platform is highly configurable by design and, as with most network devices, many default configurations are insecure.

As with traditional infrastructure, it is commonplace for system administrators to sacrifice security for convenience. Additionally, this technology is still relatively immature and, therefore, the security of it is less understood than traditional infrastructure; this highlights why reviewing the configuration of these services is important. It should also be noted that with the cloud, certain services must be exposed to the internet (for example, authentication to the cloud account that controls access and privileges) which would usually only be accessible from the internal corporate network.

ZeroDayLab provides configuration reviews for all three of the major cloud services (Amazon’s AWS, Microsoft’s Azure, and Google’s G Suite). These configuration reviews provide the customer with a level of assurance that their account(s) are configured securely and in line with industry best practice. This is ideal as it ensures any data hosted with these providers is secure - not only from outsider compromise but also from insider threats originating from the provider.

Configuration reviews and penetration tests

Configuration reviews can be coupled with infrastructure penetration tests; combining these two security assessments enhances the result of each. With access to the cloud account the consultant can retrieve all the information related to the account and use that to target the infrastructure; this is very useful as penetration tests must be performed in a limited timeframe. With permission to attack the infrastructure, certain attack paths and methods can be fully tested. Being able to attack the infrastructure also allows for the assessment of the services being hosted on the virtual instances, the result of which can affect the risk of related findings, for example traffic filtering and segregation (which are generally discovered during a configuration review).

During a previous configuration review and combined infrastructure assessment, ZeroDayLab discovered overly permissive network access control lists in place, allowing anyone on the internet access to a docker registry service, being hosted within one of the virtual instances to deploy containers. After further testing, this docker instance was found to be configured insecurely and could be used by any unauthenticated attacker to upload malicious images. These could have then been used to deploy containers within the victim company’s cloud infrastructure, leading to a complete compromise of the infrastructure, with the possibility of pivoting to internal corporate systems, resulting in the theft of sensitive customer data.

The scenario described above is a specific example of how an insecurely configured cloud service can cause serious damage to services and put customer data at risk, while demonstrating the importance of combining a configuration review with a security assessment of the infrastructure.

Wednesday 17 July 2019

The Power of Social Engineering, Part Two: In the Crosshairs of an Attacker

Written by Stuart Peck

In the previous blog post we covered the fundamentals of social engineering, from Cialdini’s 6 Principles of Influence through to how attackers leverage social engineering. In this article we will cover the techniques and tactics used to profile a target using Open Source Intelligence, and how this information can be used to generate highly effective pretexts. We will also briefly cover some of the other types of social engineering attacks. In the final article we will cover how you can detect and, more importantly, protect yourself from a range of attacks that use social engineering.

What is OSINT?

To understand how attackers build profiles on their targets, we must first dive into the wonderful world of open-source intelligence or OSINT.

“Open-source intelligence (OSINT) is data collected from publicly available sources to be used in an intelligence context. In the intelligence community, the term ‘open’ refers to overt, publicly available sources (as opposed to covert or clandestine sources). It is not related to open-source software or collective intelligence.” -Wikipedia

There’s a saying that goes, “if you have nothing to hide, you have nothing to fear.” The reality is that everyone has something they want to hide from the general public or, more aptly, an attacker. The key is identifying what form this information is in, how well protected it is, and if compromised, what the personal / professional impact would be.

Attackers are constantly profiling targets, looking for potential weaknesses in security and, from personal experience, it can take less than 1 hour of online recon using manual and automated OSINT techniques to gather enough information on a target to learn their:

·         Full Name
·         Location
·         SSN / NI number
·         Date of Birth
·         Email Accounts and Passwords
·         Mother’s Maiden Name
·         Online Digital Footprint
·         Employment Information
·         Financial Information
·         Mobile / Work Telephone Numbers
·         Social Media Information / Posts
·         Family / Friends / Colleagues
·         Interests
·         Work ID / Passes
·         Online Usernames for Third Party Sites / Forums

Armed with the above information, a motivated attacker could do some serious damage – especially as many people reuse passwords, and the same email as a login for multiple web apps or use an email / username that can identify something about you, such as year of birth.

A lot of the aforementioned information can be gathered with ease by using Google (or DuckDuckGo, Bing, etc.) but combine this with a powerful set of Open Source tools, it can be automated to perform at scale, even with manual verification. Below is a diagram depicting the tools and methodology for performing recon on an organisation.

All this information is extremely useful in the hands of a skilled social engineer, as it can be used to create a highly effective pretext or provide context for building an ongoing campaign against an organisation and its key employees / stakeholders.

What Is Pretexting?

Pretexting is a form of social engineering where the attacker uses information already obtained through OSINT or other sources to build a fabricated scenario to convince a target to disclose information or perform an action that is not in their own best interest.

Capable social engineers will often convince their targets to perform actions that enable the attacker to gain unauthorised access to information or physical access to restricted areas of a building. There are many times where I have gained unauthorised access to buildings in a range of industries such as financial services, e-commerce, gambling, pharma, and retail by using very simple pretexts and plenty of confidence. The key to good pretexting is in the research conducted beforehand and looking / sounding the part; without this any decent security guard or employee will easily see through the scenario and deny access.

There are many case studies on pretexting, but the most notable is the cybergang group Crackas With Attitude (CWA) who, in 2016, used social engineering to impersonate their victims by calling their cell phone carrier using basic verification such as the last 4 digits of the victim’s social security number. CWA were able to gain access to sensitive information, including emails, using this to further compromise their targets. In more than one case they accessed secret information from the CIA and FBI, and even John Brennan’s (the then CIA Director) personal email, and cell phone accounts. It was reported that the attackers also leaked information about 20,000 LEA (Law Enforcement Agency) officers, though this was never fully proven.

Although the attackers were caught and then subsequently prosecuted, it shows how effective vishing using basic pretexting and OSINT can be, even in the hands of high school kids.

Pretexting utilises most of the core principles of influence, but is weighted more on Authority and Social Proof, to build credibility with their targets.

What is Baiting?

Baiting, as the name suggests, is used to exploit a target’s peaked curiosity; an attacker will offer something (usually free) to lure a victim into clicking a link or running a malicious application. Classic examples of baiting include USB drops, or more recently, competitions on social media where malicious apps are found to steal login tokens or cause information leakage. Memes are also used for baiting, as many popular memes found on the internet have been found to contain some form of adware or malware.

If it seems too good to be true, then it probably is.

Baiting is heavily weighted on the use of Social Proof and Scarcity / Urgency to manipulate targets.

What is Quid Pro Quo?

In the simplest term possible, quid pro quo means “something for something” in Latin; today this means the exchange of goods or services, or a favour for a favour, and it’s the latter we will focus in on this article.

Today, quid pro quo is used in highly effective marketing campaigns, especially at conferences, where exhibitors will offer free merchandise, usually for the exchange of information (say, a business card or scanning a badge - which will contain valuable contact information). The exchange is definitely weighted in the favour of the exhibitor, but the attendee is still getting what they want - the free t-shirt or some branded lightsaber (talking from recent con experience here).

Social engineering scammers, especially Tech Support scammers, use quid pro quo to great effect. They call an unsuspecting victim and tell them they have a virus, but because they are from Microsoft, they can fix the issue. Usually this is either a free service as the objective is to drop a banking trojan, or there is a fee payable to have ongoing “support” (because they “fixed” the non-existent issue). The victim (usually a vulnerable person), then feels obliged to pay for the service not received.

I know of a close friend whose parents were scammed out of £25,000 using a similar scam, but under the guise of a BT fraud department working with their bank. They convinced the victims to transfer the money to a temporary holding, so they could investigate the compromised router and to protect their bank account which had been compromised; they felt obliged because the attacker fixed an issue on the work laptop and router. It was a basic but convincing scam; unfortunately, the money was lost and unrecoverable by the bank, even when the victims finally realised the mistake and contacted the bank. The scammers called for 2+ days even after they scammed the victims, still using the same pretext.

Attackers using quid pro quo leverage the use of Reciprocity and Commitment in their attacks.

In Summary

There are many types of social engineering attacks, such as phishing, spear phishing, whaling, and tailgating. Each attack vector is highly effective given the right amount of research conducted by the attacker. The attack surface for social engineering is huge within most organisations. However, defending against these attacks relies upon a fine balance between training, technology, and the correctly implemented policies and procedures. This is a subject that will be covered in detail in our final post in the series.