Top 10 Malware January 2020

Top 10 Malware composition was very consistent with December 2019 with only a few new additions to the list. Of note Nemucod made an appearance in the Top 10 despite remaining relatively quiet since 2017. Overall, the Top 10 Malware variants comprised just 53% of Total Malware activity in January, up slightly from 48% in December. ZeuS and its variants drive the number of infections to start out the new year. Emotet infections continue to comprise only a small portion of the Top 10 despite very active distribution campaigns. This suggests SLTT governments are finding success in detecting and preventing Emotet infections.




In January 2020, malware delivered via malspam accounted for the greatest number of alerts in the Top 10 malware list. The level of activity in the malspam and multiple categories indicates an increase over the previous month. However, Malspam activity remains lower than the highs observed in October driven by TrickBot and Emotet infections among SLTT governments. The ZeuS, CryptoWall, and CoinMiner alerts account for activity within the multiple infection vector category for the month. Kovter, Dridex, NanoCore, Cerber, Nemucod, and Emotet drive malspam related infections for the month of January. Gh0st is currently the only malware in the Top 10 whose primary initiation vector is being dropped by other malware. There is a high likelihood that malspam will continue to remain the preferred initiation vector for malware in the Top 10.


Dropped – Malware delivered by other malware already on the system, an exploit kit, infected third-party software, or manually by a cyber threat actor. Currently Gh0st is being dropped.

Multiple – Malware that currently favors at least two vectors. ZeuS, CryptoWall, and CoinMiner are currently utilizing multiple vectors. ZeuS is dropped by other malware, but it is also delivered via malvertisement. CoinMiner utilizes the malspam and dropped vectors

Malspam – Unsolicited emails, which either direct users to malicious web sites or trick users into downloading or opening malware. Top 10 Malware using this technique Kovter, Dridex, NanoCore, Cerber, Nemucod, and Emotet.

Network – Malware introduced through the abuse of legitimate network protocols or tools, such as SMB protocol or remote PowerShell. WannaCry uses this vector.


  1. ZeuS is a modular banking trojan which uses keystroke logging to compromise victim credentials when the user visits a banking website. Since the release of the ZeuS source code in 2011, many other malware variants have adopted parts of it’s codebase, which means that events classified as ZeuS may actually be other malware using parts of the ZeuS code.
  2. Dridex is a banking trojan that uses malicious macros in Microsoft Office with either malicious embedded links or attachments. Dridex is disseminated via malspam campaigns.
  3. Kovter is a fileless click fraud malware and a downloader that evades detection by hiding in registry keys. Reporting indicates that Kovter can have backdoor capabilities and uses hooks within certain APIs for persistence.
  4. CoinMiner is a cryptocurrency miner that uses Windows Management Instrumentation (WMI) and EternalBlue to spread across a network. CoinMiner uses the WMI Standard Event Consumer scripting to execute scripts for persistence. CoinMiner spreads through malspam or is dropped by other malware.
  5. Cerber is an evasive ransomware that is capable of encrypting files in offline mode and is known for fully renaming files and appending them with a random extension. There are currently six versions of Cerber, which evolved specifically to evade detection by machine learning algorithms. Currently, version 1 is the only version of Cerber for which a decryptor tool is available.
  6. Gh0st is a RAT used to control infected endpoints. Gh0st is dropped by other malware to create a backdoor into a device that allows an attacker to fully control the infected device.
  7. NanoCore is a RAT spread via malspam as a malicious Excel XLS spreadsheet. As a RAT, NanoCore can accept commands to download and execute files, visit websites, and add registry keys for persistence.
  8. Nemucod is a trojan that downloads additional malware onto an infected system. It is primarily spread via malspam and is known to drop ransomware such as Teslacrypt.
  9. Emotet is a modular infostealer that downloads or drops banking trojans. It can be delivered through either malicious download links or attachments, such as PDF or macro-enabled Word documents. Emotet also incorporates spreader modules in order to propagate throughout a network. In January 2018, Emotet was observed using a new module that exfiltrates email content.
  10. CryptoWall is a ransomware commonly distributed through malspam with malicious ZIP attachments, Java Vulnerabilities, and malicious advertisements. Upon successful infection, CryptoWall will scan the system for drive letters, network shares, and removable drives. CryptoWall runs on both 32-bit and 64-bit systems.