April 2023’s Most Wanted Malware: Qbot Launches Substantial Malspam Campaign and Mirai Makes its Return

Check Point Research uncovered a substantial malspam campaign for Trojan Qbot, which came in second in last month’s threat index. Meanwhile Internet-of-Things (IoT) malware Mirai made it back on the list for the first time in a year, and Healthcare moved up to become the second most exploited industry

Our latest Global Threat Index for April 2023 saw researchers uncover a substantial Qbot malspam campaign distributed through malicious PDF files, attached to emails seen in multiple languages. Meanwhile, Internet-of-Things (IoT) malware Mirai made the list for the first time in a year after exploiting a new vulnerability in TP-Link routers, and Healthcare moved up to become the second most exploited industry.

The Qbot campaign seen last month involves a new delivery method in which targets are sent an email with an attachment that contains protected PDF files. Once these are downloaded, the Qbot malware is installed on the device. Researchers found instances of the malspam being sent in multiple different languages, which means organizations can be targeted worldwide.

Last month also saw the return of Mirai, one of the most popular IoT malwares. Researchers discovered it was exploiting a new zero-day vulnerability CVE-2023-1380 to attack TP-Link routers and add them to its botnet, which has been used to facilitate some of the most disruptive distributed DDoS attacks on record. This latest campaign follows an extensive report published by Check Point Research (CPR) on the prevalence of IOT attacks.

There was also a change in impacted industries, with healthcare overtaking government as the second most exploited sector in April. Attacks on healthcare institutions have been well documented and some countries continue to face constant assaults. For example, cybercriminal group Medusa recently launched attacks on cancer facilities in Australia. The industry remains a lucrative target for hackers as it gives them potential access to confidential patient data and payment information. It could have implications for pharmaceutical companies as it could lead to leaks regarding clinical trials or new medical drugs and devices.

Cybercriminals are constantly working on new methods to bypass restrictions and these campaigns are further proof of how malware adapts to survive. With Qbot on the offensive again, it acts as another reminder of the importance of having comprehensive cybersecurity in place, and due diligence when it comes to trusting the origins and intent of an email.

CPR also revealed that “Web Servers Malicious URL Directory Traversal” was the most exploited vulnerability, impacting 48% of organizations globally, followed by “Apache Log4j Remote Code Execution” with 44% and “HTTP Headers Remote Code Execution” with a global impact of 43%.

Top malware families

*The arrows relate to the change in rank compared to the previous month.

AgentTesla was the most prevalent malware last month with an impact of 10% worldwide organizations, followed by Qbot with a global impact of 7% and Formbook with a global impact of 6%.

1. ↑ AgentTesla – AgentTesla is an advanced RAT functioning as a keylogger and information stealer, which is capable of monitoring and collecting the victim’s keyboard input, system keyboard, taking screenshots, and exfiltrating credentials to a variety of software installed on a victim’s machine (including Google Chrome, Mozilla Firefox and the Microsoft Outlook email client).
2. ↓ Qbot – Qbot AKA Qakbot is a banking Trojan that first appeared in 2008. It was designed to steal a user’s banking credentials and keystrokes. Often distributed via spam email, Qbot employs several anti-VM, anti-debugging, and anti-sandbox techniques to hinder analysis and evade detection.
3. ↔ Formbook – Formbook is an Infostealer targeting the Windows OS and was first detected in 2016. It is marketed as Malware as a Service (MaaS) in underground hacking forums for its strong evasion techniques and relatively low price. FormBook harvests credentials from various web browsers, collects screenshots, monitors and logs keystrokes, and can download and execute files according to orders from its C&C.
4. ↓ Emotet – Emotet is an advanced, self-propagate and modular Trojan. Emotet once used to be employed as a banking Trojan, and recently is used as a distributor to other malware or malicious campaigns. It uses multiple methods for maintaining persistence and Evasion techniques to avoid detection. In addition, it can be spread through phishing spam emails containing malicious attachments or links.
5. ↑ GuLoader – Guloader is a downloader that has been widely used since December 2019. When it first appeared, GuLoader was used to download Parallax RAT but has been applied to other remote access trojans and info-stealers such as Netwire, FormBook, and AgentTesla.
6. ↓ XMRig – XMRig is open-source CPU mining software used to mine the Monero cryptocurrency. Threat actors often abuse this open-source software by integrating it into their malware to conduct illegal mining on victims’ devices.
7. ↑ Nanocore – NanoCore is a Remote Access Trojan that targets Windows operating system users and was first observed in the wild in 2013. All versions of the RAT contain basic plugins and functionalities such as screen capture, crypto currency mining, remote control of the desktop and webcam session theft.
8. ↑ Phorpiex – Phorpiex is a botnet (aka Trik) that has been active since 2010 and at its peak controlled more than a million infected hosts. It is known for distributing other malware families via spam campaigns as well as fueling large-scale spam and sextortion campaigns.
9. ↓ Remcos – Remcos is a RAT that first appeared in the wild in 2016. Remcos distributes itself through malicious Microsoft Office documents, which are attached to SPAM emails, and is designed to bypass Microsoft Windows UAC security and execute malware with high-level privileges.
10. ↑Mirai- Mirai is an infamous Internet-of-Things (IoT) malware that tracks vulnerable IoT devices, such as web cameras, modems and routers, and turns them into bots. The botnet is used by its operators to conduct massive Distributed Denial of Service (DDoS) attacks. The Mirai botnet first surfaced in September 2016 and quickly made headlines due to some large-scale attacks including a massive DDoS attack used to knock the entire country of Liberia offline, and a DDoS attack against the Internet infrastructure firm Dyn, which provides a significant portion of the United States internet’s infrastructure.

Top Attacked Industries Globally

Last month, Education/Research remained the most attacked industry globally, followed by Healthcare and Government/Military.

1. Education/Research
2. Healthcare
3. Government/Military

Top exploited vulnerabilities

Last month, “Web Servers Malicious URL Directory Traversal” was the most exploited vulnerability, impacting 48% of organizations globally, followed by “Apache Log4j Remote Code Execution” impacting 44% of organizations worldwide and “HTTP Headers Remote Code Execution” with a global impact of 43%.

1. ↑ Web Servers Malicious URL Directory Traversal – There exists a directory traversal vulnerability on different web servers. The vulnerability is due to an input validation error in a web server that does not properly sanitize the URI for the directory traversal patterns. Successful exploitation allows unauthenticated remote attackers to disclose or access arbitrary files on the vulnerable server.
2. ↓ Apache Log4j Remote Code Execution (CVE-2021-44228) – A remote code execution vulnerability exists in Apache Log4j. Successful exploitation of this vulnerability could allow a remote attacker to execute arbitrary code on the affected system.
3. ↓ HTTP Headers Remote Code Execution (CVE-2020-10826,CVE-2020-10827,CVE-2020-10828,CVE-2020-13756) – HTTP headers let the client and the server pass additional information with an HTTP request. A remote attacker may use a vulnerable HTTP Header to run arbitrary code on the victim machine.
4. ↑ Command Injection Over HTTP (CVE-2021-43936,CVE-2022-24086) – A command Injection over HTTP vulnerability has been reported. A remote attacker can exploit this issue by sending a specially crafted request to the victim. Successful exploitation would allow an attacker to execute arbitrary code on the target machine.

5. ↓ MVPower DVR Remote Code Execution – A remote code execution vulnerability exists in MVPower DVR devices. A remote attacker can exploit this weakness to execute arbitrary code in the affected router via a crafted request. ↔ PHP Easter Egg Information Disclosure – An information disclosure vulnerability has been reported in the PHP pages. The vulnerability is due to incorrect web server configuration. A remote attacker can exploit this vulnerability by sending a specially crafted URL to an affected PHP page.
6. ↓ OpenSSL TLS DTLS Heartbeat Information Disclosure (CVE-2014-0160,CVE-2014-0346) – OpenSSL TLS DTLS Heartbeat Information DisclosureAn information disclosure vulnerability exists in OpenSSL. The vulnerability, aka Heartbleed, is due to an error when handling TLS/DTLS heartbeat packets. An attacker can leverage this vulnerability to disclose memory contents of a connected client or server.
7. ↓ Dasan GPON Router Authentication Bypass (CVE-2018-10561) – An authentication bypass vulnerability exists in Dasan GPON routers. Successful exploitation of this vulnerability would allow remote attackers to obtain sensitive information and gain unauthorized access into the affected system.
8. ↑ D-Link Multiple Products Remote Code Execution (CVE-2015-2051) – A remote code execution vulnerability exists in multiple D-Link products. Successful exploitation of this vulnerability could allow a remote attacker to execute arbitrary code on the affected system.
9. ↓ PHP Easter Egg Information Disclosure – An information disclosure vulnerability has been reported in the PHP pages. The vulnerability is due to incorrect web server configuration. A remote attacker can exploit this vulnerability by sending a specially crafted URL to an affected PHP page.
10. ↔ WordPress portable-phpMyAdmin Plugin Authentication Bypass (CVE-2012-5469) – An authentication bypass vulnerability exists in WordPress portable-phpMyAdmin Plugin. Successful exploitation of this vulnerability would allow remote attackers to obtain sensitive information and gain unauthorized access into the affected system.

Top Mobile Malwares

Last month, Ahmyth remained in top spot as the most prevalent mobile malware, followed by Anubis and Hiddad.

1. AhMyth – AhMyth is a Remote Access Trojan (RAT) discovered in 2017. It is distributed through Android apps that can be found on app stores and various websites. When a user installs one of these infected apps, the malware can collect sensitive information from the device and perform actions such as keylogging, taking screenshots, sending SMS messages, and activating the camera.
2. Anubis – Anubis is a banking Trojan malware designed for Android mobile phones. Since it was initially detected, it has gained additional functions including Remote Access Trojan (RAT) functionality, keylogger, audio recording capabilities and various ransomware features. It has been detected on hundreds of different applications available in the Google Store.
3. Hiddad – Hiddad is an Android malware which repackages legitimate apps and then releases them to a third-party store. Its main function is to display ads, but it can also gain access to key security details built into the OS.

Check Point’s Global Threat Impact Index and its ThreatCloud Map is powered by Check Point’s ThreatCloud intelligence. ThreatCloud provides real-time threat intelligence derived from hundreds of millions of sensors worldwide, over networks, endpoints and mobiles. The intelligence is enriched with AI-based engines and exclusive research data from Check Point Research, the intelligence and research Arm of Check Point Software Technologies.