Top 10 Malware of August 2017
In August 2017, the Top 10 Malware was made up approximately 49% of new malware infections reported by the MS-ISAC, an increase of three percentage points from July, and the first monthly increase since peaking at 56% of new malware notifications in April 2017. This coincided with a 13% increase in the number of Top 10 Malware notifications sent in August 2017 compared to July 2017. Every month the MS-ISAC maps the Top 10 Malware to common infection vectors. This is done by using open source observations and reports on each malware type. The MS-ISAC observed an increase in malspam in August due to a continued increase in Emotet activity. There were also slight increases in dropped malware and in malvertisement activity.
The MS-ISAC Top 10 Malware refers to the top 10 new actionable event notifications of non-generic malware signatures sent out by the MS-ISAC Security Operations Center (SOC).
Dropped – Malware dropped by other malware already on the system or by an exploit kit.
Malvertising – Malware introduced through a malicious advertisement.
Multiple – Refers to malware that currently favors at least two vectors.
Malspam – Unsolicited emails, which either direct users to download malware from malicious websites or trick the user into opening malware through an attachment.
- Emotet is a malware banking variant that uses malicious macros with either malicious embedded links or attachments. Emotet is in the same family of malware as Dridex and was regionally isolated in Europe around Germany. In early-April 2017, a campaign targeted the United Kingdom (UK) before surfacing in the United States in mid-April 2017. Emotet is disseminated via malspam campaigns. A recent evolution in functionality adds spreader modules to Emotet. This builds on a recent trend of adding propagation tools and techniques to ransomware that crimeware is adopting.
- Kovter is a Trojan, which has been observed acting as click fraud malware or a ransomware downloader. It is disseminated via malspam email attachments containing malicious office macros. Kovter is fileless malware that evades detection by hiding in registry keys. Some reports indicate that Kovter infections have received updated instructions from command and control infrastructure to serve as a remote access backdoor.
- ZeuS/Zbot 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/Zbot source code in 2011, many other malware variants have adopted parts of its codebase, which means that events classified as ZeuS/Zbot may actually be other malware using parts of the ZeuS/Zbot code.
- DNSChanger is malware that was very prolific in the late 2000s and early 2010s, before being dismantled by a FBI takedown. A new variant was identified in December 2017, which reportedly acts as an exploit kit targeting routers. Once infected, the routers’ DNS records are modified to point to a malicious server. DNSChanger is disseminated via malvertising and uses steganography to obfuscate its initial actions.
- Hancitor is downloader malware disseminated via phishing emails containing a malicious macro attachment and is known to obfuscate itself using PowerShell commands.
- PCRat/Gh0st is a Remote Access Trojan (RAT) used to control infected endpoints. PCRat is dropped by other malware to create a backdoor into a device to allow an attacker to fully control the infected device.
- TinyNuke is a banking malware using webpage injection to harvest user credentials. The creator released the source code on Github, potentially allowing for the modification and further weaponization of the code by other cyber threat actors.
- VirLock is a ransomware with virus capabilities that not only encrypts files but creates a .exe “copy” of the file in the same directory that is loaded with the virus. The most recent version can also spread through cloud sync, cloud storage, and collaboration applications.
- Ponmocup is a downloader associated with one of the largest and longest-running botnets, active since 2006. Ponmocup is usually disseminated through an infected web page as a malvertisement.
- Ramnit is a modular banking Trojan which employs web injection capabilities sourced from the Zeus Trojan. Additional modules allow Ramnit to steal cookies, grant remote access, and exfiltrate files. This variant emerged in 2010 and activity peaked in 2014, and has since maintained a low but steady presence. Ramnit is distributed via infected files on public FTP servers, exploit kits, and malvertisments.