SolarWinds releases updated advisory for SUPERNOVA backdoor

Pierluigi Paganini December 27, 2020

SolarWinds released an updated advisory for the SuperNova malware discovered while investigating the recent supply chain attack.

SolarWinds has released an updated advisory for the SuperNova backdoor that was discovered while investigating the recent SolarWinds Orion supply-chain attack.

The SuperNova backdoor was likely used by a separate threat actor.

After the initial disclosure of the SolarWinds attack, several teams of researchers mentioned the existence of two second-stage payloads.

Security experts from SymantecPalo Alto Networks, and Guidepoint reported that threat actors behind the SolarWinds attack were also planting a .NET web shell dubbed Supernova.

Researchers from Palo Alto Networks revealed that the malicious code is a tainted version of the legitimate .NET library “app_web_logoimagehandler.ashx.b6031896.dll” included in the SolarWinds Orion software.

“In the analysis of the trojanized Orion artifacts, the .NET .dll app_web_logoimagehandler.ashx.b6031896.dll was dubbed SUPERNOVA, but little detail of its operation has been publicly explored.” reads the analysis published by Palo Alto Networks.

“SUPERNOVA differs dramatically in that it takes a valid .NET program as a parameter. The .NET class, method, arguments and code data are compiled and executed in-memory. There are no additional forensic artifacts written to disk, unlike low-level webshell stagers, and there is no need for additional network callbacks other than the initial C2 request. In other words, the SolarStorm attackers have constructed a stealthy and full-fledged .NET API embedded in an Orion binary, whose user is typically highly privileged and positioned with a high degree of visibility within an organization’s network.”

This week, SolarWinds published an updated advisory about the SUPERNOVA backdoor, it includes details about the way it was distributed through the SolarWinds Orion network management platform.

“The SUPERNOVA malware consisted of two components. The first was a malicious, unsigned webshell .dll “app_web_logoimagehandler.ashx.b6031896.dll” specifically written to be used on the SolarWinds Orion Platform. The second is the utilization of a vulnerability in the Orion Platform to enable deployment of the malicious code.” reads the updated advisory. “The vulnerability in the Orion Platform has been resolved in the latest updates.”

SolarWinds urges Orion Platform customers, except those ones already on Orion Platform versions 2019.4 HF 6 or 2020.2.1 HF 2, to apply the latest updates related to the version of the product they have deployed.

The updates include the following versions:

  • 2019.4 HF 6 (released December 14, 2020)
  • 2020.2.1 HF 2 (released December 15, 2020)
  • 2019.2 SUPERNOVA Patch (released December 23, 2020)
  • 2018.4 SUPERNOVA Patch (released December 23, 2020)
  • 2018.2 SUPERNOVA Patch (released December 23, 2020)

For customers that have already upgraded to the 2020.2.1 HF 2 or 2019.4 HF 6 versions, they cannot be infected with SUNBURST and SUPERNOVA.

SolarWinds provided the following recommendations for the several versions of the SolarWinds Orion Platform:

Orion Platform VersionKnown Affected by SUNBURST?Known Vulnerable to SUPERNOVA?Recommended ActionDirect Link
Orion Platform 2020.2.1 HF 2NONONo action neededNo action needed
Orion Platform 2020.2.1 HF 1NOYESUpgrade to 2020.2.1 HF 2customerportal.solarwinds.com
Orion Platform 2020.2.1NOYESUpgrade to 2020.2.1 HF 2customerportal.solarwinds.com
Orion Platform 2020.2 HF 1YESYESUpgrade to 2020.2.1 HF 2customerportal.solarwinds.com
Orion Platform 2020.2YESYESUpgrade to 2020.2.1 HF 2customerportal.solarwinds.com
Orion Platform 2019.4 HF 6NONONo action neededNo action needed
Orion Platform 2019.4 HF 5YESYESUpgrade to 2019.4 HF 6
(or upgrade to 2020.2.1 HF 2)
customerportal.solarwinds.com
Orion Platform 2019.4 HF 4NOYESUpgrade to 2019.4 HF 6
(or upgrade to 2020.2.1 HF 2)
customerportal.solarwinds.com
Orion Platform 2019.4 HF 3NOYESUpgrade to 2019.4 HF 6
(or upgrade to 2020.2.1 HF 2)
customerportal.solarwinds.com
Orion Platform 2019.4 HF 2NOYESUpgrade to 2019.4 HF 6
(or upgrade to 2020.2.1 HF 2)
customerportal.solarwinds.com
Orion Platform 2019.4 HF 1NOYESUpgrade to 2019.4 HF 6
(or upgrade to 2020.2.1 HF 2)
customerportal.solarwinds.com
Orion Platform 2019.4NO*YESUpgrade to 2019.4 HF 6
(or upgrade to 2020.2.1 HF 2)
customerportal.solarwinds.com
Orion Platform 2019.2 HF 3NOYESUpgrade to 2020.2.1 HF 2
(or apply 2019.2 HF 3 Security Patch)
To upgrade, go to customerportal.solarwinds.com

Or, to apply security patch go to: 
https://downloads.solarwinds.com/solarwinds/Release/HotFix/2019.2_HF3_SecurityFix.zip
Orion Platform 2019.2 HF 2NOYESUpgrade to 2020.2.1 HF 2
(or upgrade to 2019.2 HF 3 AND apply 2019.2 HF 3 Security Patch)
To upgrade, go to customerportal.solarwinds.com

Or, to apply security patch go to: 
https://downloads.solarwinds.com/solarwinds/Release/HotFix/2019.2_HF3_SecurityFix.zip
Orion Platform 2019.2 HF 1NOYESUpgrade to 2020.2.1 HF 2
(or upgrade to 2019.2 HF 3 AND apply 2019.2 HF 3 Security Patch)
To upgrade, go to customerportal.solarwinds.com

Or, to apply security patch go to: 
https://downloads.solarwinds.com/solarwinds/Release/HotFix/2019.2_HF3_SecurityFix.zip
Orion Platform 2019.2NOYESUpgrade to 2020.2.1 HF 2
(or upgrade to 2019.2 HF 3 AND apply 2019.2 HF 3 Security Patch)
To upgrade, go to customerportal.solarwinds.com

Or, to apply security patch go to: 
https://downloads.solarwinds.com/solarwinds/Release/HotFix/2019.2_HF3_SecurityFix.zip
Orion Platform 2018.4NOYESUpgrade to 2020.2.1 HF2 (or ensure you are running 2018.4 HF3 AND apply the 2018.4 HF3 Security Patch)To upgrade, go to customerportal.solarwinds.com

Or, to apply security patch go to:
 https://downloads.solarwinds.com/solarwinds/Release/HotFix/2018.4_HF3_SecurityFix.zip
Orion Platform 2018.2NOYESUpgrade to 2020.2.1 HF2 (or ensure you are running 2018.2 HF6 AND apply the 2018.2 HF6 Security Patch)To upgrade, go to customerportal.solarwinds.com

Or, to apply security patch go to: 
https://downloads.solarwinds.com/solarwinds/Release/HotFix/2018.2_HF6_SecurityFix.zip
All prior versionsNOYESDiscontinue use
(or upgrade to 2020.2.1 HF 2)
customerportal.solarwinds.com

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Pierluigi Paganini

(SecurityAffairs – hacking, SUPERNOVA)

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