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Threat Spotlight: Rombertik – Gazing Past the Smoke, Mirrors, and Trapdoors

This post was authored by Ben Baker and Alex Chiu.

Executive Summary

Threat actors and security researchers are constantly looking for ways to better detect and evade each other.  As researchers have become more adept and efficient at malware analysis, malware authors have made an effort to build more evasive samples.  Better static, dynamic, and automated analysis tools have made it more difficult for attackers to remain undetected. As a result, attackers have been forced to find methods to evade these tools and complicate both static and dynamic analysis.

Table of Contents
Executive Summary
The 10,000 Foot View at Rombertik
Analysis
A Nasty Trap Door
The Actual Malware
Coverage and Indicators of Compromise
Conclusion

It becomes critical for researchers to reverse engineer evasive samples to find out how attackers are attempting to evade analysis tools. It is also important for researchers to communicate how the threat landscape is evolving to ensure that these same tools remain effective. A recent example of these behaviors is a malware sample Talos has identified as Rombertik. In the process of reverse engineering Rombertik, Talos discovered multiple layers of obfuscation and anti-analysis functionality. This functionality was designed to evade both static and dynamic analysis tools, make debugging difficult. If the sample detected it was being analyzed or debugged it would ultimately destroy the master boot record (MBR).

Talos’ goal is to protect our customer’s networks.  Reverse engineering Romberik helps Talos achieve that goal by better understanding how attackers are evolving to evade detection and make analysis difficult.  Identifying these techniques gives Talos new insight and knowledge that can be communicated to Cisco’s product teams.  This knowledge can then be used to harden our security products to ensure these anti-analysis techniques are ineffective and allow detection technologies to accurately identify malware to protect customers. Read More »

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The Cisco Security Dojo

Over the past three years, Cisco has invested in the creation of an application security awareness program. The program helps the good citizens of this company understand, apply, and act upon a strategy to build more trustworthy products. We launched the existence of the program to the world at the RSA Conference 2015. I am sharing this with you because we’ve created something unique to the industry, and we want to encourage other companies to pursue the creation of an application security awareness program.

When you think about security awareness, do you envision phishing e-mails, Nigerian princes, and tailgating cyber criminals? Security vulnerabilities are a fact of life, but we can help our organizations develop a greater level of understanding and a desire to put security first in their development efforts. At Cisco, we believe that security awareness training should feature traditional training about crazy links you should not click under any circumstances and how to stop strangers from entering your buildings, as well as application security awareness. Application security awareness, when done well, can drive security culture change to make a company and its products and solutions safer. Moving an organization to focus on security is possible, because we have done it.

Enough talking about it, please take a sneak peek at how we do it here in this video.

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The Rise in Healthcare Cybercrime

Cybercrime1January this year witnessed the largest healthcare breach to date in which the personal records of 80 million individuals were compromised. It also marked an apparent change in focus from attacks on delivery organizations to healthcare payers. Last week two additional health insurers reported that they too had been hacked, resulting in the possible compromise of a further 11.25 million personal records. In a period of less than 3 months, the US has seen over 91 million records and personal identities stolen from healthcare insurers alone.

The health insurers appear to have been the target of highly sophisticated cyber attacks perpetrated from China, which involved the use of advanced persistent threats (APTs) and spear phishing. This allowed them to gain administrative credentials that were used to exfiltrate stolen data via the use of common cloud data services.

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Threat Spotlight: TeslaCrypt – Decrypt It Yourself

This post was authored by: Andrea Allievi, Earl Carter & Emmanuel Tacheau

Update 4/28: Windows files recompiled with backward compatibility in Visual Studio 2008

Update 5/8: We’ve made the source code available via Github here

After the takedown of Cryptolocker, we have seen the rise of Cryptowall. Cryptowall 2 introduced “features” such as advanced anti-debugging techniques, only to have many of those features removed in Cryptowall 3. Ransomware is becoming an extremely lucrative business, leading to many variants and campaigns targeting even localized regions in their own specific languages. Although it is possible that these multiple variants are sponsored by the same threat actor, the most likely conclusion is that multiple threat actors are jumping in to claim a portion of an ever increasing ransomware market. One of the latest variants is called TeslaCrypt and appears to be a derivative of the original Cryptolocker ransomware. Although it claims to be using asymmetric RSA-2048 to encrypt files, it is making use of symmetric AES instead. Talos was able to develop a tool which decrypts the files encrypted by the TeslaCrypt ransomware.

 

TeslaCrypt-1

Click for Larger Image

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Best Practices: Device Hardening and Recommendations

On April 13th, 2015, Cisco PSIRT was made aware of multiple instances of customer disruption in a specific region caused by a denial of service attack against Cisco devices. We responded quickly to support speedy restoration for our customers.

Our ongoing investigation has shown that the storage of some Cisco devices was erased, removing both the Cisco IOS and device configuration from the non-volatile RAM. Once rebooted, these devices became non-operational, affecting connectivity to the global Internet.

Cisco PSIRT, together with other internal Cisco teams, responded to support affected customers, review configuration backups of affected devices, and to analyze all available log files and Netflow information.

At this time, we have seen a common element across all inspected devices: a combination of weak credentials and a lack of device hardening. There has been no evidence of a Cisco bug or vulnerability being exploited. Should this situation change and we discover the use of a vulnerability, Cisco will disclose in accordance with our Security Vulnerability Policy.

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