Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.


04:55 AM
Gadi Evron
Gadi Evron
Connect Directly

Cybercriminals: More Obvious Than They Think?

Attackers often use and abuse security by obscurity, which can lessen the likelihood that they will be caught. From them we can learn a lot about profiling attackers on our networks, and how they work to achieve better operational security. Take their use of encryption.

Attackers often use and abuse security by obscurity, which can lessen the likelihood that they will be caught. From them we can learn a lot about profiling attackers on our networks, and how they work to achieve better operational security. Take their use of encryption.Being obscure, attackers hope to avoid detection or compromise. The best example in recent years is binary packers.

When virus authors use packers to obfuscate and encrypt their new worm or bot, they have two achievements in mind: alluding detection by antivirus products, and making it much harder for virus researchers and reverse engineers to unravel how their malware works, thus taking more time to create detection signatures in the first place.

Let me pose it this way: It's a hot summer day, and you're drinking a beer at the beach. People are having fun and relaxing. Suddenly, you see a person wearing an heavy coat. Is this suspicious?

Most likely that is not common behavior, and your answer is YES! Now, it does not necessarily mean that person is a terrorist, but it's not a bad idea to call the police.

In much the same way, if a gateway antivirus vendor collects and correlates information from clients (while filtering billions of email messages every day), "seeing" an executable email attachment that is "packed" arouses suspicion. This sample can be marked as suspicious and tested further.

For clarification, plenty of legitimate products use packers, so false positives will occur. On the desktop antivirus, this is not a great idea.

The goal of the smart attacker is to appear like a normal user, much like a spy would try and appear inconspicuous. Many attackers are not smart. Bots are far from common users in behavior.

Packers are a form of encryption. Encryption illustrates the preceding example. If you're a spy and want to send a message to your handlers using email, then would you use encryption?

Encryption is a great tool, but it also draws attention to you for using it. In your organization, how likely is an attacker to identify important resources just by watching for encrypted traffic? In some cases, it may be better to stay obscure, in the background as noise, than to use encryption. If the malware sample is new and therefore undetected by antivirus, then the same unfortunately applies to malware authors.

Encryption is, indeed, a great tool, but it is not a cure-all. It requires a risk analysis on your part -- much like any other solution.

Even if you decide encryption is an added value by default, there are other uses for the concept that it helped us illustrate. Ask yourself: What do attackers mostly look like? Do they have something in common you should be looking for?

This is often referred to as anomaly detection, only you can use it not just in deep packet inspection, but in daily operations -- much like looking for the guy wearing a heavy coat in the summer.

Knowing what your network looks like and what traffic is typical is the most basic and most critical in corporate network security.

Two random examples of possible anomalies:

    1. Should Web servers be talking to each other in the server farm? 2. Should the firewall be surfing the Web?

What are yours?

You can read the first in this series of articles here and the second here.

Follow Gadi Evron on Twitter: http://twitter.com/gadievron

Gadi Evron is an independent security strategist based in Israel. Special to Dark Reading. Gadi is CEO and founder of Cymmetria, a cyber deception startup and chairman of the Israeli CERT. Previously, he was vice president of cybersecurity strategy for Kaspersky Lab and led PwC's Cyber Security Center of Excellence, located in Israel. He is widely recognized for ... View Full Bio

Comment  | 
Print  | 
More Insights
Newest First  |  Oldest First  |  Threaded View
Data Leak Week: Billions of Sensitive Files Exposed Online
Kelly Jackson Higgins, Executive Editor at Dark Reading,  12/10/2019
Lessons from the NSA: Know Your Assets
Robert Lemos, Contributing Writer,  12/12/2019
4 Tips to Run Fast in the Face of Digital Transformation
Shane Buckley, President & Chief Operating Officer, Gigamon,  12/9/2019
Register for Dark Reading Newsletters
White Papers
Current Issue
The Year in Security: 2019
This Tech Digest provides a wrap up and overview of the year's top cybersecurity news stories. It was a year of new twists on old threats, with fears of another WannaCry-type worm and of a possible botnet army of Wi-Fi routers. But 2019 also underscored the risk of firmware and trusted security tools harboring dangerous holes that cybercriminals and nation-state hackers could readily abuse. Read more.
Flash Poll
Rethinking Enterprise Data Defense
Rethinking Enterprise Data Defense
Frustrated with recurring intrusions and breaches, cybersecurity professionals are questioning some of the industrys conventional wisdom. Heres a look at what theyre thinking about.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
PUBLISHED: 2019-12-15
In the Linux kernel before 5.3.11, sound/core/timer.c has a use-after-free caused by erroneous code refactoring, aka CID-e7af6307a8a5. This is related to snd_timer_open and snd_timer_close_locked. The timeri variable was originally intended to be for a newly created timer instance, but was used for ...
PUBLISHED: 2019-12-15
python-requests-Kerberos through 0.5 does not handle mutual authentication
PUBLISHED: 2019-12-15
CFME (CloudForms Management Engine) 5: RHN account information is logged to top_output.log during registration
PUBLISHED: 2019-12-15
jersey: XXE via parameter entities not disabled by the jersey SAX parser
PUBLISHED: 2019-12-15
JBoss KeyCloak: Open redirect vulnerability via failure to validate the redirect URL.