Tuesday, 21 June 2011

APT in a nutshell

APT in a Nutshell

Recently I had the chance to present at Owasp AppSec EU (http://www.appseceu.org/) on the topic of APT (Advanced Persistent Threat). The talk went down well and as such here is a follow up based on my slides and the questions raised by the audience


To be fair, I have a love - hate relationship with the term APT. It is used to describe state sponsored espionage, which i know exists and can be a significant threat to specific entities such as government departments and defence contractors. I’m also aware of APT style attacks on corporate organisations. However, the term can be banded around and badly applied to security ‘hacks’ as well as being seen as a ‘China’ only issue. This is especially true when dealing with the media and specific security vendors. This is the side of APT that I hate.

So what is APT anyway?

APT is used to describe a variety of attacks but has its origins in what would be categorised as state sponsored cyber espionage. This traditional cyber espionage was concentrated on government agencies and supporting defence contractors. This has been extended to encompass a wider focus, resulting in what is known today as APT.

The objective of APT is to;

  • Gain access to information,

  • Maintain access to gather large quantities of data,

  • To serve a specific set of goals / objectives.

APT stands for Advanced Persistent Threat. So what do these terms really mean? A number of definitions exist, but from my perspective I see APT as:

Advanced – This relates to the ability of the attacker. It doesn’t however mean that they will only use custom created code to launch what is known as ‘zero day’ attacks on a network. It is important to understand that they will use the path of least resistance when looking to compromise a network. If this can be done through trivially guessable passwords then this is the method they will use, but they have the capability to research and develop new attack code if required.

Persistent – This is a key differentiator with other threat actors. The aim of those conducting APT is to gain access to information. The information that is targeted is of greatest value when gathered in volume. APT attacks therefore seek to maintain access to the network for as long as is required to achieve this. Smash and grab attacks, such as those that target credit card information fall within a different class of threat actor, and should not be confused with APT. However, APT style attacks could be completed in such a fashion if they are able to meet their objectives with one short attack.

Threat – The use of the term threat within the context of APT relates to the fact that this is a targeted attack, which is directed to achieve a defined purpose and has both the intent and capability to gain access to the desired information.

So how does APT differ from cybercrime?

There is a degree of cross-over between cybercrime and APT. Highly capable threat actors within both areas are highly organised, well-motivated and funded. This makes both these actors a real threat. The key difference between an attack being classified as APT or cybercrime is the intention or driver of the behind attack.

The Hype

APT has become over hyped and this has been used to sell products and services based on the APT threat.
As an example, major security vendors now sell anti-APT services and products, with strap lines such as:

“Do You Know if Your Network Has Been Breached by Botnets, Advanced Malware or Persistent Threats?”

"threats such as the Advanced Persistent Threat (APT). These are one of the most dangerous types of threats"

"Introduces New Security Solutions to Counter Advanced Persistent Threats"

"Enterprise Computer Protection from Advanced Malware Threats/APT"

"New Security Solutions to Counter Advanced Persistent Threats"

In a recent press release, Tom Reilly (CEO of ArcSight.Symantec) explained that revenue for the second quarter is expected to be in the range of $55 million to $57 million (that is 21%-25% growth over the same quarter last year). This is based partly on “growing cybercriminal activity and heightened awareness of the Advanced Persistent Threat”.

Even the media carry provocative statements:

“The APT attackers, however, employ undetectable zero-day exploits and social engineering techniques against company employees to breach networks.”

All of this feeds on the fear, uncertainty and doubt that exists around the term APT and implies the big bad guys are going to get you, regardless of who you are! Media focus is clearly on China and how they are behind all APT attacks. However this paints a very narrow picture of the reality and is predicated by the belief that all APT is state sponsored and worse, that China are the only players.

The Reality

In reality the threat is wider than that posed by ‘China’, in fact evidence leaked as part of the WikiLeaks stories showed that the US believed that “French espionage is so widespread that the damages [it causes] the German economy are larger as a whole than those caused by China or Russia.” (http://www.ibtimes.com/articles/97534/20110104/france-wikileaks-spying-germany.htm)

If we look more closely at APT, we can see that it falls into two categories. Firstly with its roots firmly as a method of cyber-espionage, it was focused on gaining government information and this would clearly be an activity undertaken by nation states. Secondly as a style of attack that is broadly aligned to gaining access to intellectual property (IP) and commercially sensitive data. This second category indicates that APT style attacks may not just be the preserve of state sponsored entities.

The aim of targeting commercial IP is to gain access to knowledge that can provide a competitive edge, such as blue prints, merger information and strategy documents. This type of information would give competitors an advantage over their rivals and this is the real driving force behind the wider use of attacks classed as APT. These motivating factors could be attributed to individual organisations as well as governments pursuing economic growth.

Are you at risk?

If we listen to the hype then we are all at risk, even the mighty Google and the IMF have fallen foul of APT! Then again we are not all in the same market as Google (with all its sensitive customer data) or the IMF. So the first question to ask yourself is; do you hold information that someone is willing to spend time and effort in trying to obtain? If the answer is no, then you can sleep soundly in bed at night. Well, from an APT perspective at least.

I believe that we are at the most risk when we are looking in the wrong direction. Before we became aware of APT, organisations assessed that commercial data that had no value from a cybercrime or fraud perspective wouldn't be a target in a hack. As a result, breaches went unnoticed. However, this continues to be the case. Why therefore do the attacks go unnoticed, how do they breach the network in the first place? In my opinion a lot of this is down to the wrong focus within the organisation and in what they are trying to protect (if anything!).

What do I mean by this? Well, within the UK we have a number of regulatory drivers that help organisations focus their priorities. The Information Commissioner and Data Protection requirements keep an organisation focused on protecting personal sensitive data. Financial regulation and PCI-DSS keep others focused on protecting financial data, however there is no requirement other than an individual organisations risk appetite in terms of protecting intellectual property. This is exactly what those conducting APT are targeting. They are going for something you didn’t think to protect. You made a risk based decision to focus on regulatory drivers, they made the decision to target your corporate network and steal as much data as they could and then see what was useful.


So what is the solution? How do we defend against APT? In reality, in the same way you defend against other cyber threats, through resilient information security. This will depend on how a business approaches risk management, the level of assurance required and based on organisation's risk appetite.

Any approach taken should be driven by a clear business need and understanding of the risk environment and the organisation's risk management structure. The business needs to be aware of the threat environment that they are in and be able to make informed decisions, and not just be blinkered into making regulatory based decisions only.

We also need to accept that we are not able to achieve 100% security, especially through appliance based solutions or by just doing penetration testing or by being regulatory compliant. Instead we should approach this problem from the point of view of business resiliency, which captures the ability for an organisation to be robust to attack and to be able to detect / react / recover from an incident.