This report is provided "as is" for informational purposes only. The Department of Homeland Security (DHS) does not provide any warranties of any kind regarding any information contained herein. The DHS does not endorse any commercial product or service referenced in this bulletin or otherwise.
This document is marked TLP:WHITE--Disclosure is not limited. Sources may use TLP:WHITE when information carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for public release. Subject to standard copyright rules, TLP:WHITE information may be distributed without restriction. For more information on the Traffic Light Protocol (TLP), see http://www.cisa.gov/tlp.
CISA received one unique file for analysis. This file contains a malicious shell script recovered from a compromised Pulse Secure device. This malicious script is designed to modify the Pulse Secure login.cgi script effectively causing it to log a valid user's username and password credentials into a file stored on disk. This analysis is derived from malicious files found on Pulse Connect Secure devices.
For a downloadable copy of indicators of compromise, see: MAR-10333243-3.v1.stix.
Submitted Files (1)
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This shell script was utilized by the attacker to modify the Pulse Secure system script named login.cgi. The modifications to the application login.cgi are performed using the Linux sed command. These modifications are primarily designed to cause the system application to log a user's password and username credentials to a file when the user logs into a compromised Pulse Secure device. The credentials can then be retrieved by the attacker. These stolen credentials may be utilized as a means to easily access the compromised Pulse Secure device remotely, or to pivot to other systems and networks. The sed commands utilized by this script to modify login.cgi are illustrated below.
CISA recommends that users and administrators 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.
Additional information on malware incident prevention and handling can be found in National Institute of Standards and Technology (NIST) Special Publication 800-83, "Guide to Malware Incident Prevention & Handling for Desktops and Laptops".
CISA continuously strives to improve its products and services. You can help by answering a very short series of questions about this product at the following URL: https://us-cert.cisa.gov/forms/feedback/
What is a MIFR? A Malware Initial Findings Report (MIFR) is intended to provide organizations with malware analysis in a timely manner. In most instances this report will provide initial indicators for computer and network defense. To request additional analysis, please contact CISA and provide information regarding the level of desired analysis.
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 CISA 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 CISA at 1-888-282-0870 or CISA Service Desk.
Can I submit malware to CISA? Malware samples can be submitted via three methods:
CISA 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 CISA's homepage at www.cisa.gov.
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