TA17-164A: HIDDEN COBRA – North Korea’s DDoS Botnet Infrastructure

Original release date: June 13, 2017 | Last revised: August 23, 2017

Systems Affected

Networked Systems

Overview

This joint Technical Alert (TA) is the result of analytic efforts between the Department of Homeland Security (DHS) and the Federal Bureau of Investigation (FBI). This alert provides technical details on the tools and infrastructure used by cyber actors of the North Korean government to target the media, aerospace, financial, and critical infrastructure sectors in the United States and globally. Working with U.S. Government partners, DHS and FBI identified Internet Protocol (IP) addresses associated with a malware variant, known as DeltaCharlie, used to manage North Korea’s distributed denial-of-service (DDoS) botnet infrastructure. This alert contains indicators of compromise (IOCs), malware descriptions, network signatures, and host-based rules to help network defenders detect activity conducted by the North Korean government. The U.S. Government refers to the malicious cyber activity by the North Korean government as HIDDEN COBRA. For more information related to HIDDEN COBRA activity, go to )

IOCs ()

MAR IOCs ( and Guardians of Peace. Wild Positron/Duuzer, DHS has previously released Alert TA14-353A, This malware has used the IP addresses identified in the accompanying .csv and .stix files as both source and destination IPs. In some instances, the malware may have been present on victims’ networks for a significant period.

Technical Details

DeltaCharlie is a DDoS tool used by HIDDEN COBRA actors, and is referenced and detailed in Novetta’s Operation Blockbuster Destructive Malware report. The information related to DeltaCharlie from the Operation Blockbuster Destructive Malware report should be viewed in conjunction with the IP addresses listed in the .csv and .stix files provided within this alert. DeltaCharlie is a DDoS tool capable of launching Domain Name System (DNS) attacks, Network Time Protocol (NTP) attacks, and Carrier Grade NAT (CGN) attacks. The malware operates on victims’ systems as a svchost-based service and is capable of downloading executables, changing its own configuration, updating its own binaries, terminating its own processes, and activating and terminating denial-of-service attacks. Further details on the malware can be found in Novetta’s report available at the following URL:

Revision History

• June 13, 2017: Initial Release


• August 23, 2017: Updated YARA Rules and included MAR-10132963 (.pdf and .stix files)

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