Today we’re examining some of the revelations in the Q3 Cisco Talos Incident Response Trends Report. This document is an anonymized look at of all the engagements that the Cisco Talos Incident Response team have been involved in over the previous three months. It also features threat intelligence from our team of researchers and analysts.  

To start, take a watch of this episode of ThreatWise TV which explores how these trends have evolved since the previous quarter. Our guests also talk about incidents and cyber-attacks that they themselves have consulted on recently, including a particularly interesting insider threat case. 

Highlights of the Q3 Cisco Talos Incident Response report 

Ransomware returned as the top threat this quarter, after commodity trojans narrowly surpassed ransomware last quarter. Ransomware made up nearly 18 percent of all threats observed, up from 15 percent last quarter. Cisco Talos Incident Response (CTIR) observed high-profile families, such as Vice Society and Hive, as well as the newer family Blast Basta, which first emerged in April of this year.   

Also noteworthy is the fact that CTIR saw an equal number in ransomware and pre- ransomware engagements this quarter, totalling nearly 40 percent of threats observed. Pre-ransomware is when we have observed a ransomware attack is about to happen, but the encryption of files has not yet taken place. 

Pre-ransomware comprised 18 percent of threats this quarter, up from less than 5 percent previously. While it’s difficult to determine an adversary’s motivations if encryption does not take place, several behavioral characteristics bolster Talos’ confidence that ransomware may likely be the final objective. In these engagements adversaries were observed deploying frameworks such as Cobalt Strike and Mimikatz, alongside numerous enumeration and discovery techniques.  

Commodity malware, such as the Qakbot banking trojan, was observed in multiple engagements this quarter. In one engagement, several compromised endpoints were seen communicating with IP addresses associated with Qakbot C2 traffic. This activity coincides with a general resurgence of Qakbot and its delivery of emerging ransomware families and offensive security frameworks that we have not previously observed Qakbot deploy. This comes at a time where competing email-based botnets like Emotet and Trickbot have suffered continued setbacks from law enforcement and tech companies.  

Other threats this quarter include infostealers like Redline Stealer and Raccoon Stealer. Redline Stealer was observed across three engagements this quarter, two of which involved ransomware. The malware operators behind Raccoon introduced new functionality to the malware at the end of June, which likely contributed to its increased presence in engagements this quarter.  

As infostealers have continued to rank highly in CTIR engagements, let’s explore them in a bit more detail. 

Why infostealers proliferate  

Throughout the incidents discussed over the last few quarters, and CTIR engagements in general, information stealing plays a big part of the attackers’ TTPs.   

From a high level, infostealers can be used to gain access a variety of sensitive information, such as contact information, financial details, and even intellectual property. The adversaries involved often proceed to exfiltrate this information and may then attempt to sell it in dark web forums, threaten to release it if a ransom isn’t paid, among other things.  

While these instances can and do crop up in CTIR engagements, many of the infostealers seen in this space are used for accessing and collecting user credentials. Once an attacker has gained an initial foothold on a system, there are many places within an operating system that they can look for and collect credentials through the practice of credential dumping.   

These stolen credentials may be offered up for sale on the dark web, alongside the stolen information mentioned above, but they can also prove to be a key weapon in an attacker’s arsenal. Their usefulness lies in one simple concept—why force your way into a system when you can just log in?  

There are several advantages for bad actors that use this approach. Probably the most oblivious of these is that using pre-existing credentials is far more likely to go unnoticed than other more flagrant tactics an attacker can use. If part of the goal of an attack is to remain under the radar, activities carried out by “known users” are less likely to trigger security alerts when compared to tactics such as exploiting vulnerabilities or downloading malware binaries.  

Adversaries tend to seek credentials with higher privileges, allowing them further control over the systems they compromise, with those including administrative access being the crown jewels.  

User credentials can not only provide an attacker with means to elevate privileges and establish persistence on a system, but also to move laterally through a network. Some credentials, especially those with administrative privileges, can offer access to multiple systems throughout a network. By obtaining them, many more options become available to further an attack.  

Repeat offenders  

There are several threats involved in information stealing that appear repeatedly in CTIR engagements over the last few quarters.  

Perhaps the most notorious is Mimikatz—a tool used to pull credentials from operating systems. Mimikatz is not malware per-se and can be useful for penetration testing and red team activities. But bad actors leverage it as well, and over the last few quarters CTIR has observed it being used in ransomware-as-a-service attacks, as well as pre-ransomware incidents.   

CTIR has also observed Redline Stealer being utilized by adversaries in CTIR engagements across quarters. This infostealer has grown in popularity as a supplementary tool used alongside other malware. On more than one occasion, CTIR has identified stolen credentials on the dark web that claimed to have been obtained via Redline Stealer.  

Other information stealers seen across the last few quarters include the Vidar information stealer, Raccoon Stealer, and SolarMaker, all of which have been used to further an adversary’s attacks.   

Insider threats 

Over the last several months, Talos has seen an increasing number of engagements involving insider threats. In one engagement this quarter, passwords were reset through a management console of a perimeter firewall that a disgruntled employee had access to.   

The organization’s team changed all associated passwords but overlooked one administrative account. On the following day, someone logged in using that account, deleted all other accounts and firewall rules, and created one local account, likely to provide persistence.  

You’ll hear Alexis Merritt, Incident Response Consultant for Cisco Talos, talk about this more in the ThreatWise TV episode. 

To help protect against this threat when an individual leaves an organization, steps like disabling accounts and ensuring that connections to the enterprise remotely through VPN has been removed can be very valuable. Implementing a mechanism to wipe systems, especially for remote employees, is important as well.  

For more on this topic, Cisco Secure recently put together a white paper on the Insider Threat Maturity FrameWork.

How to protect  

In several incidents over the last few quarters that involved information stealers, multi-factor authentication (MFA) was not properly implemented by the organizations impacted, providing adversaries an opportunity to infiltrate the networks. MFA tools like Cisco Secure Access by Duo can prevent attackers from successfully gaining access. 

Connecting with Wolfgang Goerlich 

And finally, Cisco Advisory CISO Wolfgang Goerlich has created this storytelling video, to help people think about incident response in a new way: 

Join the Cisco Talos Incident Response team for a live debrief of the Q3 report on 27th October. 

We’d love to hear what you think. Ask a Question, Comment Below, and Stay Connected with Cisco Secure on social!

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