Crimeware, an emerging sub-class of the more general malware, is mainly focused on facilitating financial gain for the hacker. Crimeware typically operates through direct sniffing of financially relevant data, including payment card information, passwords, and bank account numbers. This information is then used to build more complex attacks, including silent, back-door account withdrawals or the creation of physical debit cards to perform ATM withdrawals.
Two of the largest and most publicized payment card breaches of late are suspected to be incidents involving crimeware: RBS Worldpay and Heartland Payment Systems. Heartlands' breach went undetected for nearly six months exposing more than 100 million payment cards serviced for 175,000 merchants. RBS acknowledged losing 1.5 million customers' financial data from its payroll cards business. This information was in turn used to withdraw over $9 million from ATMs across the globe. These and similar attacks, such as the Russian Coreflood Gang attacks, all have the hallmarks of crimeware.
These events show as much as any that crime, in fact, does pay. A significant amount of today's hackers are financially driven. As the code and attacks are effectively criminalized, the “community” has identified the need to also commercialize crimeware. Tools and attacks get more advanced, easier to use, come bundled with related tools, documentation, and even come with technical support. Crimeware is not a “hack” as much as it is a systematic attack against a series of weaknesses. Crimeware represents a growing problem in network security, as many malicious code threats work together, seeking to pilfer financial information and funds.
So what can companies do to ensure they aren't a victim? Does PCI compliance ensure proper security coverage? No CSO wants to hear they have a malware issue, and certainly not that the malware is actually crimeware.
The nice thing about the PCI DSS is that it is essentially the embodiment of a defense-in-depth philosophy – multiple overlapping security controls in an attempt to avoid severe weaknesses in any one area. What is key to remember is that PCI enforces compliance with the DSS, not necessarily best practice security.
First we need to understand how crimeware can infiltrate your network and systems. Many people suffer from the preconceived notion that crimeware infection happens only by opening an infected attachment. But that is only one compromise vector. An infected PC can spread its payload as a worm in an organization, abusing local vulnerabilities or configurations. A user can visit a trusted websites that is hosting compromised/malicious online advertisements that can be used to transmit crimeware. Phishing messages containing external links and shareware software installations can create crimeware infections. The bottom line is that you have to defend multiple paths into your network and systems. So, the question remains: What can you do to prevent such an event in the first place?
The most important aspect to preventing malware is ensuring your organization has a comprehensive, up-to-date anti-virus (AV) program. Ensuring that all users have up-to-date AV controls that cover not only virus, but spyware and malware, is critical. For example, Symantec sells two completely separate products to protect for virus and malware. Just having their virus protection isn't enough as it doesn't cover iInternet-based malware. So, yes, if you are one of those companies that have removed client-based virus scanning —only checking at the email gateway and the servers, you now have a problem. Check that your organization has proper anti-virus/anti-spyware/anti-malware coverage and that the status of updates is actively monitored and validated. Doing so, by the way, also gets you PCI DSS 5.1.1 compliant.
System patching and hardening
Malware will often spread like a worm once it infects a network. Some spread by taking advantage of common vulnerabilities or configuration weaknesses. Ensuring your systems are patched in a timely manner and hardened using a recognized guide, such as the one produced by the National Security Agency, can greatly minimize the spread of crimeware if a PC does get infected.
Malvertising, combined with internet surfing, is a great way for infection to happen. Ensuring that users update their browser as appropriate, as well as their browser plug-ins (i.e., Adobe Flash), which are well known sources of security holes, is another critical aspect to system patching that companies often overlook.
And, doing this properly gets you PCI DSS 4.1 (partly), 6.1, 6.3.1, and 6.4 compliant.
Use of security plug-ins in the browser
While on the topic of browser plug-ins, a great addition to the security toolbox is the use of those that prevent ads and scripts from running (Flashblock, No Script, Adblock) and thus infecting a machine. While this isn't a PCI requirement, it is certainly a great security practice.
Data-leakage prevention systems
DLP is an enterprise-level security tool that monitors internet traffic, looking for sensitive data leaving or entering your network. It isn't a silver bullet but can be a powerful control to help monitor (or block) the spread of financial, personal or corporate data if an infection does happen. Once again, while DLP is not a PCI requirement, it is a powerful security tool.
File and kernel integrity monitoring (FIM)
FIM builds a snapshot of the files contained on your system when it is in a known good state. For crimeware to work, it has to infect your machine, typically by installing an executable or shared library. If your FIM detects a change in a file (like the size and/or date of an executable), that is an indication that the file has been changed by malware. You have to monitor the right folders/files, but it's an effective layer of security. Proper FIM integration is a requirement within PCI DSS 10.5.5.
Database and transport encryption
Simply put, if the data is encrypted properly, it is of no use to criminals even if they do access it. If it is transmitted properly over encrypted channels, it makes access to sensitive data much more difficult. This is the backbone to PCI and is covered by PCI DSS 3.1, 3.2.X, 3.3, 3.4, 3.5, 4.1.X and so forth.
Increased user awareness
The importance of solid user awareness cannot be overlooked. Having users trained on secure email and Internet usage, including education about new risks, is key. In addition, users that understand the sensitivity of the data they work with and the compliance obligations of the organization can take precautions consistent with the organizations security and compliance program. This is a mandate from PCI within PCI DSS 12.6.X.
Proper log monitoring
Proper log monitoring is the cornerstone of any good security program. Several of the solutions above are merely detection mechanisms. If your security group isn't monitoring the logs at least daily then all the controls in the world won't do much good if the threats go unchecked. Not every attack can be prevented, but early detection is guaranteed to minimize the damage done. This is especially true in the case of crimeware where early detection can prevent hackers from having the necessary time to gather information needed to build a more complex attack. This is a major component to PCI and is addressed in the PCI DSS 10.X, 11.4, and 12.5.2.
Mandatory access control (MAC)
MAC is popular in the government and is an emerging technology/process in the commercial space. Think of it as the Windows GPO on steroids. The basic tenets of MAC security are found in system hardening guides today. If you have done everything in this article, and want to do more, MAC is for you. This isn't a PCI requirement, but is yet another solid best practice.
In the event your organization is compromised, understanding the distinction between a malware infection and crimeware infection is critical. Forty-five states currently have breach disclosure laws. If your organization is infected with crimeware, depending on the depth and level of compromise, you will have both compliance and regulatory reporting guidelines to follow. Ensuring that your organization has a security and compliance program which includes security controls, log monitoring, and an incident response plan (PCI DSS 12.5.3, 12.9.X), can help minimize the financial and reputational damage done, and get you back on the road to recovery that much sooner.
Courtlend Little is a senior product manager for Solutionary, provider of managed security solutions, compliance and security measurement, and security consulting services.