SolarWinds Orion Vulnerability

Updated January 15, 2021

The U.S. Department of Homeland Security (DHS) and the Cybersecurity and Infrastructure Security Agency (CISA) have confirmed that malicious threat actors have been and are actively exploiting vulnerabilities in SolarWinds Orion products, specifically affected versions 2019.4 through 2020.2.1 HF1.

The threat actor primarily leverages a malware commonly known as SUNBURST to conduct a global supply-chain attack against the SolarWinds Orion platform. SolarWinds Orion is an enterprise-grade IT monitoring solution.

This malware was seen being distributed as part of SolarWinds Orion software updates from March 2020.  As part of the software update, this malware comes in the form of a dynamic linked library (DLL) that was digitally signed by SolarWinds.  Once loaded by legitimate SolarWinds.BusinessLayerHost.exe or SolarWinds.BusinessLayerHostx64.exe, this malware is capable of transferring data, file execution, system profiling, rebooting and more.

Apart from being digitally signed, this malware employed other evasion tactics.  These include employing Teardrop, which is a memory only dropper, to deploy a customized Cobalt Strike beacon.  It also encoded strings such as domain names, user-agents, registry keys and others.

A few of the notable encoded strings are as follows:

• 583da945-62af-10e8-4902-a8f205c72b2e -> This is the name of a named pipe which will be used as a mutex to avoid multiple instances of the malware from running.
• avsvmcloud[.]com -> one of the domain names this malware connects to.
• SolarWindsOrionImprovementClient/3.0.0.382 -> the User-Agent field the malware will use during HTTP communication to the C&C Server

The Command & Control traffic is also difficult to detect as it was designed to mimic legitimate SolarWinds API calls.  Unlike other botnet malware which connects to their C&Cs in a regular basis, SUNBURST only communicates to the malicious server once every 12 to 14 days.

SolarWinds has confirmed the attack and has asked impacted customers using Orion to immediately upgrade to 2019.4 HF 6 or 2020.2.1 HF 1. Please visit www.solarwinds.com/securityadvisory for more information about your Orion upgrade options.

Both SolarWinds and the CISA strongly suggest that organizations using SolarWinds Orion verify the version they’re running and upgrade immediately, if required.

SonicWall Capture Labs threat researchers have investigated the vulnerability and published multiple signatures in different categories that identify malicious activity against affected SolarWinds Orion versions. It includes application identification signatures that detect if an organization has SolarWinds Orion deployed within its network; malicious domain signatures; malicious IPs; malware such as Sunburst, Supernova and Teardrop. These signatures are applied automatically to SonicWall firewalls with active security subscriptions.

Application signatures – identify SolarWinds Orion applications:

• 15296: BUSINESS-APPS SolarWinds Orion (API Activity)
• 2014: BUSINESS-APPS SolarWinds Orion (Update Activity)

IPS signatures – identify malicious domains:

• 15292: SolarWinds Supply Chain Malware Activity 1
• 15293: SolarWinds Supply Chain Malware Activity 2
• 15294: SolarWinds Supply Chain Malware Activity 3
• 15295: SolarWinds Supply Chain Malware Activity 4
• 15298: SolarWinds Supply Chain Malware Activity 5
• 15299: SolarWinds Supply Chain Malware Activity 6
• 15300: SolarWinds Supply Chain Malware Activity 7
• 15301: SolarWinds Supply Chain Malware Activity 8
• 15302: SolarWinds Supply Chain Malware Activity 9
• 15303: SolarWinds Supply Chain Malware Activity 10
• 15308: SolarWinds Supply Chain Malware Activity 11
• 15309: SolarWinds Supply Chain Malware Activity 12
• 15310: SolarWinds Supply Chain Malware Activity 13
• 15311: SolarWinds Supply Chain Malware Activity 14
• 15312: SolarWinds Supply Chain Malware Activity 15
• 15313: SolarWinds Supply Chain Malware Activity 16
• 15314: SolarWinds Supply Chain Malware Activity 17
• 15315: SolarWinds Supply Chain Malware Activity 18
• 15316: SolarWinds Supply Chain Malware Activity 19
• 15317: SolarWinds Supply Chain Malware Activity 20

GAV signatures – identify malwares:

Sunburst - Backdoor malware that has been trojanized into multiple SolarWinds Orion update versions.

• SunBurst.A (Trojan) IOC:d0d626deb3f9484e649294a8dfa814c5568f846d5aa02d4cdad5d041a29d5600
• SolarWinds.DL (Trojan), IOC:ce77d116a074dab7a22a0fd4f2c1ab475f16eec42e1ded3c0b0aa8211fe858d6
• SunBurst.A_1 (Trojan), IOC:32519b85c0b422e4656de6e6c41878e95fd95026267daab4215ee59c107d6c77
• SunBurst.A_2 (Trojan), IOC:ad2fbf4add71f61173975989d1a18395afb8538ed889012b9d2e21c19e98bbd1
• SunBurst.A_3 (Trojan), IOC:019085a76ba7126fff22770d71bd901c325fc68ac55aa743327984e89f4b0134

Supernova - a webshell planted in the code of the Orion network and applications monitoring platform and enabled adversaries to run arbitrary code on machines running the trojanized versions of the software.

• Injector.DN_35 (Trojan) IOC:c15abaf51e78ca56c0376522d699c978217bf041a3bd3c71d09193efa5717c71
• Supernova.A_1 (Trojan), IOC:1c96021ac8cb52173e762f6b008fb4c6e5ef113e6baa4e2cf4848e88c61d9700

Teardrop - a memory only dropper that runs as a service

• Teardrop.B (Trojan), IOC:6e4050c6a2d2e5e49606d96dd2922da480f2e0c70082cc7e54449a7dc0d20f8d

Domain Blacklist: 

• avsvmcloud.com
• digitalcollege.org
• freescanonline.com
• deftsecurity.com
• thedoccloud.com
• virtualdataserver.com
• incomeupdate.com
• databasegalore.com
• panhardware.com

SonicWall products and real-time security services can help organizations identify and mitigate SUNBURST malware and other attacks against vulnerable SolarWinds Orion versions.

To verify you have the latest SonicWall Intrusion Prevention Signatures (IPS), please follow the steps in this knowledgebase (KB) article: https://www.sonicwall.com/support/knowledge-base/detailed-information-on-intrusion-prevention-signature-ips-signature-ids/170505742887527/