dllFake (Trojan) – Malware

Overview

In the ever-evolving landscape of cyber threats, the emergence of sophisticated malware continues to challenge traditional security measures. One such threat is the dllFake malware family, a recently identified cyber adversary known for its stealthy and multifaceted attack methods. First observed in early 2024, dllFake represents a notable evolution in malware design, incorporating a range of capabilities that make it a formidable threat to both individual users and organizations alike. This malware family was discovered following a supply chain attack targeting popular software installers, which were trojanized to deliver dllFake’s payload to unsuspecting victims. dllFake malware is characterized by its use of trojanized software installers to infiltrate systems. By leveraging compromised installation packages for widely used applications such as Notezilla, RecentX, and Copywhiz, dllFake effectively bypasses conventional security defenses, posing a significant challenge for detection and prevention. The attack vectors employed by dllFake not only undermine user trust in legitimate software sources but also highlight the increasing sophistication of cybercriminals who are able to exploit the software supply chain for their malicious purposes.

Targets

Individuals Information

How they operate

Initial Access and Execution

dllFake typically gains initial access to a victim’s system through a supply chain compromise. It is often distributed via trojanized software installers, which are legitimate-looking programs modified to include malicious payloads. When a user installs this compromised software, dllFake is executed alongside it. The initial payload runs with the same privileges as the legitimate installer, enabling the malware to evade immediate detection.

Persistence and Privilege Escalation

Once executed, dllFake establishes persistence on the infected system. One common technique involves creating scheduled tasks that ensure the malware remains active across reboots. These tasks are configured to trigger the execution of dllFake at regular intervals or system startup, ensuring continued access to the compromised machine. Although dllFake may not explicitly exploit vulnerabilities for privilege escalation, it can still attempt to gain higher-level access if the system’s security posture allows.

Defense Evasion and Credential Access

To evade detection, dllFake employs several defense evasion techniques. It often masquerades as legitimate software or uses trusted software installers, making it challenging for security tools to differentiate between genuine and malicious activity. This tactic helps the malware blend in with normal system operations. Additionally, dllFake is capable of credential dumping, targeting stored credentials from browsers and other applications to gather sensitive information. This capability enhances the malware’s ability to access other systems or accounts that might be linked to the infected machine.

Data Collection and Exfiltration

dllFake’s data collection techniques are comprehensive. It can log keystrokes and capture clipboard data, enabling it to gather sensitive information entered by the user. This data is then exfiltrated to the attacker’s servers over encrypted communication channels. The malware’s ability to securely transmit stolen data reduces the risk of detection by network monitoring tools and ensures that the extracted information reaches the attackers without interference.

Impact and Mitigation

While dllFake’s primary function is data theft, its operational tactics highlight the potential for broader impacts, including data corruption or system compromise. Effective mitigation strategies include deploying robust anti-malware solutions, monitoring for unusual scheduled tasks, and employing network security measures to detect and block unauthorized data exfiltration. Regular updates and patches to software can also help mitigate the risk of initial compromise through trojanized installers. In summary, dllFake’s operation illustrates a well-orchestrated approach to malware deployment and persistence. By understanding its tactics and techniques, security professionals can better prepare defenses and respond to threats posed by this and similar malware families.

MITRE Tactics and Techniques

Initial Access (T1071.001 – Application Layer Protocol)

Supply Chain Compromise: dllFake typically infiltrates systems through trojanized software installers. By compromising popular software installation packages, the malware gains initial access to the victim’s system.

Execution (T1203 – Exploitation for Client Execution)

Malicious Payload Execution: The malware executes its payload by leveraging the compromised installer to run malicious code on the victim’s machine.

Persistence (T1053 – Scheduled Task/Job)

Scheduled Task Creation: dllFake often establishes persistence by creating scheduled tasks that ensure the malware remains active on the infected system even after reboots.

Privilege Escalation (T1068 – Exploitation for Privilege Escalation)

Privilege Escalation Techniques: While specific details on privilege escalation methods used by dllFake are less documented, it may employ techniques to gain higher-level access within the system if necessary.

Defense Evasion (T1036 – Masquerading)

Masquerading as Legitimate Software: dllFake hides its presence by masquerading as legitimate software or using trusted software installers to avoid detection by security tools.

Credential Access (T1003 – Credential Dumping)

Data Theft: The malware includes capabilities for credential dumping, targeting stored credentials from browsers and other applications.

Collection (T1056 – Input Capture)

Keystroke Logging and Clipboard Data: dllFake can log keystrokes and capture clipboard data to gather sensitive information from the victim.

Exfiltration (T1041 – Exfiltration Over Command and Control Channel)

Data Exfiltration: It uses encrypted communication channels to exfiltrate stolen data from the compromised system to the attacker’s servers.

Impact (T1486 – Data Encrypted for Impact)

Impact on Data: While primarily a data-stealing malware, dllFake could potentially have capabilities that impact data integrity, though specific encryption for impact is not documented for this malware.

References:

• Supply Chain Compromise Leads to Trojanized Installers for Notezilla, RecentX, Copywhiz