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Summary
Description
Ten (10) files were submitted to NCCIC for analysis.
Four (4) files are malicious applications, obfuscated using a file encryption tool called Themida. When executed on a computer running Windows, the malware unpacks a payload that is loaded directly into the memory of the compromised system.
Once installed, this malware modifies the Windows Firewall to allow incoming connections and installs a proxy server application. In addition, the malware has the ability to exfiltrate data, install and run secondary payloads, and provide proxy capabilities on a compromised system.
Two (2) files are command-line utility applications. Three (3) files are applications designed to provide export functions and methods that allow the application to interact with financial systems and perform transactions. One (1) file is a log file.
Two (2) additional samples in the report include unpacked files contained within the following samples:
820ca1903a30516263d630c7c08f2b95f7b65dffceb21129c51c9e21cf9551c6 and 4a740227eeb82c20286d9c112ef95f0c1380d0e90ffb39fc75c8456db4f60756
This application is a Themida-packed 32-bit Windows executable. This application unpacks and executes a service proxy module in memory (5c0a4f9e67ced69eaea17092444b2c1a).
Analysis indicates that this proxy module accepts command-line parameters to perform its functions. The module modifies the Windows Firewall on the victim’s machine to allow for incoming connections and to force the compromised system to function as a proxy server.
The proxy module uses the following command to open a Windows Firewall port on the victim’s machine to allow for incoming connections:
The malware listens to an open port for incoming traffic. The traffic may contain instructions to perform any of the following functions:
-Retrieve information about the logon sessions, drives installed, and operating system -Search for files -Execute processes -Terminate processes -Delete files -Execute commands -Download and upload files -Read files -Write files -Compress and decompress files
This malware uses the multi-protocol file transfer library "libcurl 7.49.1" for transferring data with a URL syntax. It supports the following network protocols:
This application is a Themida--packed 64-bit Windows executable. This application unpacks and executes a service proxy module in memory (02959903cd988443e5ef519d556b34b0).
Analysis indicates that this proxy module accepts command-line parameters to perform its functions. The module modifies the Windows Firewall on the victim’s machine to allow for incoming connections and forces the compromised system to function as a proxy server.
The proxy module uses the following command to open a Windows Firewall port on the victim’s machine to allow for incoming connections:
The malware listens to an open port for incoming traffic. The traffic may contain instructions to perform any of the following functions:
-Retrieve information about the logon sessions, drives installed, and operating system -Search for files -Execute processes -Terminate processes -Delete files -Execute commands -Download and upload files -Read files -Write files -Compress and decompress files
This malware used the multi-protocol file transfer library "libcurl 7.49.1" for transferring data with a URL syntax. It supports the following network protocols:
This application is a 32-bit Windows executable. This application executes as a service named "helpsvcs." The application utilizes the Rivest Cipher 4 (RC4) encryption algorithm to encrypt configuration data. It stores a four-byte unique identifier, RC4 key, and the encrypted configuration data in the following registry:
The malware binds and listens on port 443 for incoming connections from a remote operator. No outbound connection was observed. Static analysis indicates that the malware is capable of providing remote command and control (C2) capabilities, including the ability to exfiltrate data, install and run secondary payloads, and provide proxy services on a compromised system. The malware utilizes the RC4 encryption algorithm to encrypt and decrypt a portion of its communications data to and from the remote operator.
Listed below are the types of data exfiltrated by the malware:
- network adapter information - computer name - username - systems Internet Protocol (IP) address - hard-coded value (00 00 00 04h) - current directory of the malware
- %Current directory%\malware.exe - hard-coded value (01h) - hard-coded value "PVS" - the victim's operating system information - installed drives information - the current system time
Displayed below are additional functions the malware performs based on specified commands from the remote operator:
-Retrieve information drives installed -Search for files -Execute processes -Terminate processes -Delete files -Execute commands -Download and upload files -Read files -Write files -Compress and uncompress files -Change the listening port for Remote Desktop via registry modification
This application is a malicious 64-bit Windows Dynamic Link Library (DLL), designed to run as a Windows service under Windows "svchost.exe." When executed, it searches and attempts to load and RC4-decrypt a payload from the following registry into memory:
This file is an Advanced Interactive Executive (AIX) executable intended for a proprietary UNIX operating system developed by IBM. This application injects a library into a currently running process. Figure 1 is a screenshot containing strings of interest. The strings indicate the application is a command-line utility that enables an operator to easily conduct code injection on an IBM AIX platform. Analysis indicates this application logs its usage to a log file (Figure 2).
Screenshots
Figure 1 - Screenshot of the strings of interest
Figure 2 - Application logging its usage to a log file.
This file is an AIX executable, intended for a proprietary UNIX operating system developed by IBM. This file is a library application designed to provide export functions. These functions allow an application to perform transactions on financial systems using the ISO8583 standard. A list of the ISO8583 functions is displayed in Figure 3 and Figure 4.
The file appears to be a log file generated by the usage of the application Inject API executable_e (b3efec620885e6cf5b60f72e66d908a9). The data contained in the log file is displayed in Figure 5, 6, and 7.
This file is an AIX executable, intended for a proprietary UNIX operating system developed by IBM. Figure 8 displays strings of interest. The strings contained within the file indicate it is a command-line utility. The file is designed to update a proprietary data structure on a UNIX system known as "PVPA." The code structure in Figure 9, extracted from this application, attempts to perform a raw read of this data structure from memory.
Screenshots
Figure 8 - Screenshot of the strings of interest
Figure 9 - The UNIX AIX executable attempting to perform a read on the data.
This file is an AIX executable, intended for a proprietary UNIX operating system developed by IBM. The application provides several exported methods permitting the interaction with financial systems that utilize the ISO8583 standard. A list of the ISO8583 functions is displayed in Figure 10 and Figure 11. This file is not considered malicious, but may have been used by actors for malicious purposes.
This file is a UNIX Common Object File Format (COFF) executable, a format for executable, object code, and shared libraries used on UNIX systems. The executable provides several exported methods that enable interactions with financial systems utilizing the ISO8583 standard. This file is not considered malicious but may have been used by actors for malicious purposes.
NCCIC would like to remind users and administrators to consider using the following best practices to strengthen the security posture of their organization's systems. Any configuration changes should be reviewed by system owners and administrators prior to implementation to avoid unwanted impacts.
Maintain up-to-date antivirus signatures and engines.
Keep operating system patches up-to-date.
Disable File and Printer sharing services. If these services are required, use strong passwords or Active Directory authentication.
Restrict users' ability (permissions) to install and run unwanted software applications. Do not add users to the local administrators group unless required.
Enforce a strong password policy and implement regular password changes.
Exercise caution when opening e-mail attachments even if the attachment is expected and the sender appears to be known.
Enable a personal firewall on agency workstations, configured to deny unsolicited connection requests.
Disable unnecessary services on agency workstations and servers.
Scan for and remove suspicious e-mail attachments; ensure the scanned attachment is its "true file type" (i.e., the extension matches the file header).
Monitor users' web browsing habits; restrict access to sites with unfavorable content.
Exercise caution when using removable media (e.g., USB thumbdrives, external drives, CDs, etc.).
Scan all software downloaded from the Internet prior to executing.
Maintain situational awareness of the latest threats and implement appropriate ACLs.
Additional information on malware incident prevention and handling can be found in NIST's Special Publication 800-83, Guide to Malware Incident Prevention & Handling for Desktops and Laptops.
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Document FAQ
What is a MAR? A Malware Analysis Report (MAR) is intended to provide organizations with more detailed malware analysis acquired via manual reverse engineering. To request additional analysis, please contact NCCIC and provide information regarding the level of desired analysis.
Can I edit this document? This document is not to be edited in any way by recipients. All comments or questions related to this document should be directed to the NCCIC at 1-888-282-0870 or soc@us-cert.gov.
Can I submit malware to NCCIC? Malware samples can be submitted via three methods:
NCCIC encourages you to report any suspicious activity, including cybersecurity incidents, possible malicious code, software vulnerabilities, and phishing-related scams. Reporting forms can be found on US-CERT's homepage at www.us-cert.gov.
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