Pierluigi Paganini December 29, 2020

Microsoft says that SolarWinds hackers aimed at compromising the victims’ cloud infrastructure after deploying the Solorigate backdoor (aka Sunburst).

The Microsoft 365 Defender Team revealed that the goal of the threat actors behind the SolarWinds supply chain attack was to move to the victims’ cloud infrastructure once infected their network with the Sunburst/Solorigate backdoor.

“With this initial widespread foothold, the attackers can then pick and choose the specific organizations they want to continue operating within (while others remain an option at any point as long as the backdoor is installed and undetected),” Microsoft explains.

“Based on our investigations, the next stages of the attack involve on-premises activity with the goal of off-premises access to cloud resources.”

Once deployed the backdoor, threat actors used it to steal credentials, escalate privileges, and make lateral movement within the target network to gain the ability to create valid SAML tokens. Microsoft experts reported that attackers created valid SAML tokens by stealing the SAML signing certificate or by adding or modifying existing federation trust.

Then the attackers created SAML tokens to access cloud resources and exfiltrate emails and sensitive data.

“This attack is an advanced and stealthy campaign with the ability to blend in, which could allow attackers to stay under the radar for long periods of time before being detected.” continues the post.

Recently, both US CISA and cybersecurity firm Crowdstrike released free detection tools to audit Azure and MS 365 environments.

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Pierluigi Paganini

(SecurityAffairs – hacking, SolarWinds)

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