Today, Talos is publishing a glimpse into the most prevalent threats we've observed between Sept. 4 and Sept. 11. As with previous roundups, this post isn't meant to be an in-depth analysis. Instead, this post will summarize the threats we've observed by highlighting key behavioral characteristics, indicators of compromise, and discussing how our customers are automatically protected from these threats.
As a reminder, the information provided for the following threats in this post is non-exhaustive and current as of the date of publication. Additionally, please keep in mind that IOC searching is only one part of threat hunting. Spotting a single IOC does not necessarily indicate maliciousness. Detection and coverage for the following threats is subject to updates, pending additional threat or vulnerability analysis. For the most current information, please refer to your Firepower Management Center, Snort.org, or ClamAV.net.
For each threat described below, this blog post only lists 25 of the associated file hashes and up to 25 IOCs for each category. An accompanying JSON file can be found here that includes the complete list of file hashes, as well as all other IOCs from this post. A visual depiction of the MITRE ATT&CK techniques associated with each threat is also shown. In these images, the brightness of the technique indicates how prevalent it is across all threat files where dynamic analysis was conducted. There are five distinct shades that are used, with the darkest indicating that no files exhibited technique behavior and the brightest indicating that technique behavior was observed from 75 percent or more of the files.
The most prevalent threats highlighted in this roundup are:
Upatre is a malicious downloader often used by exploit kits and phishing campaigns. Upatre downloads and executes malicious executables, such as banking malware.
Razy is oftentimes a generic detection name for a Windows trojan. It collects sensitive information from the infected host and encrypt the data, and send it to a command and control (C2) server. Information collected might include screenshots. The samples modify auto-execute functionality by setting and creating a value in the registry for persistence.
Gandcrab is ransomware that encrypts documents, photos, databases and other important files using the file extension ".GDCB," ".CRAB" or ".KRAB". Gandcrab is spread through traditional spam campaigns and multiple exploit kits, including Rig and Grandsoft.
Emotet is one of the most widely distributed and active malware families today. It is a highly modular threat that can deliver a wide variety of payloads. Emotet is commonly delivered via Microsoft Office documents with macros, sent as attachments on malicious emails.
Kovter is known for its fileless persistence mechanism. This family of malware creates several malicious registry entries that store its malicious code. Kovter is capable of reinfecting a system, even if the file system has been cleared of the infection. Kovter has been used in the past to spread ransomware and click-fraud malware.
Dridex is a well-known banking trojan that steals credentials and other sensitive information from an infected machine.
Indicators of Compromise
IOCs collected from dynamic analysis of 35 samples
IP Addresses contacted by malware. Does not indicate maliciousness
Cisco AMP for Endpoints protects users from a variety of malware functions with exploit prevention. Exploit prevention helps users defend endpoints from memory attacks commonly used by obfuscated malware and exploits. These exploits use certain features to bypass typical anti-virus software, but were blocked by AMP thanks to its advanced scanning capabilities, even protecting against zero-day vulnerabilities.
Dealply adware detected - (16731)
DealPly is adware, which claims to improve your online shopping experience. It is often bundled into other legitimate installers and is difficult to uninstall. It creates pop-up advertisements and injects advertisements on webpages. Adware has also been known to download and install malware.
CVE-2019-0708 detected - (2528)
An attempt to exploit CVE-2019-0708 has been detected. The vulnerability, dubbed BlueKeep, is a heap memory corruption which can be triggered by sending a specially crafted Remote Desktop Protocol (RDP) request. Since this vulnerability can be triggered without authentication and allows remote code execution, it can be used by worms to spread automatically without human interaction.
Process hollowing detected - (2393)
Process hollowing is a technique used by some programs to avoid static analysis. In typical usage, a process is started and its obfuscated or encrypted contents are unpacked into memory. The parent then manually sets up the first stages of launching a child process, but before launching it, the memory is cleared and filled in with the memory from the parent instead.
An attempt to bypass application whitelisting via the "Squiblydoo" technique has been detected. This typically involves using regsvr32.exe to execute script content hosted on an attacker controlled server.
Crystalbit-Apple DLL double hijack was detected. During this attack, the adversary abuses two legitimate vendor applications, such as CrystalBit and Apple, as part of a dll double hijack attack chain that starts with a fraudulent software bundle and eventually leads to a persistent miner and in some cases spyware deployment.
Excessively long PowerShell command detected - (619)
A PowerShell command with a very long command line argument that may indicate an obfuscated script has been detected. PowerShell is an extensible Windows scripting language present on all versions of Windows. Malware authors use PowerShell in an attempt to evade security software or other monitoring that is not tuned to detect PowerShell based threats.
Installcore adware detected - (274)
Install core is an installer which bundles legitimate applications with offers for additional third-party applications that may be unwanted. The unwanted applications are often adware that display advertising in the form of popups or by injecting into browsers and adding or altering advertisements on webpages. Adware is known to sometimes download and install malware.
Trickbot malware detected - (264)
Trickbot is a banking Trojan which appeared in late 2016. Due to the similarities between Trickbot and Dyre, it is suspected some of the individuals responsible for Dyre are now responsible for Trickbot. Trickbot has been rapidly evolving over the months since it has appeared. However, Trickbot is still missing some of the capabilities Dyre possessed. Its current modules include DLL injection, system information gathering, and email searching.
Gamarue malware detected - (230)
Gamarue is a family of malware that can download files and steal information from an infected system. Worm variants of the Gamarue family may spread by infecting USB drives or portable hard disks that have been plugged into a compromised system.
Kovter injection detected - (203)
A process was injected into, most likely by an existing Kovter infection. Kovter is a click fraud Trojan that can also act as an information stealer. Kovter is also file-less malware meaning the malicious DLL is stored inside Windows registry and injected directly into memory using PowerShell. It can detect and report the usage of monitoring software such as wireshark and sandboxes to its C2. It spreads through malicious advertising and spam campaigns.