{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/tags/aws-sts/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["AWS STS","AWS CloudTrail","AWS IAM"],"_cs_severities":["high"],"_cs_tags":["cloud-security","aws-sts","privilege-escalation","cloud","aws"],"_cs_type":"advisory","_cs_vendors":["Amazon Web Services"],"content_html":"\u003cp\u003eThis brief details the detection of suspicious \u003ccode\u003eAssumeRoot\u003c/code\u003e actions within Amazon Web Services (AWS) environments, a technique adversaries exploit for privilege escalation. When attacker-compromised user credentials are used to invoke the \u003ccode\u003eAssumeRoot\u003c/code\u003e action, it allows them to temporarily assume the root member account role, granting elevated access to specified AWS resources. This particular detection focuses on identifying instances where this action is performed by a user or principal that rarely assumes this role, or against a member account that is not typically targeted by that principal. Such activity can signify privilege escalation, lateral movement into new accounts, or the abuse of cross-account access paths, posing a significant risk of unauthorized access, data compromise, and resource manipulation within the AWS infrastructure.\u003c/p\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eA successful \u003ccode\u003eAssumeRoot\u003c/code\u003e action by an unauthorized entity grants them temporary but highly privileged access to the targeted AWS member account. This can lead to a wide array of damaging outcomes, including the creation of persistent backdoors via IAM changes (e.g., creating new users, modifying roles), disabling security controls like CloudTrail or GuardDuty to evade detection, or directly manipulating and exfiltrating sensitive data from services like S3, RDS, or DynamoDB. The blast radius can be significant, affecting core infrastructure, intellectual property, and customer data. Without timely detection and response, such an incident can result in severe financial loss, regulatory penalties, and reputational damage for the victim organization.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the Sigma rules in this brief to your SIEM and tune for your environment to detect suspicious \u003ccode\u003eAssumeRoot\u003c/code\u003e actions.\u003c/li\u003e\n\u003cli\u003eEnsure comprehensive AWS CloudTrail logging is enabled for all \u003ccode\u003ests.amazonaws.com\u003c/code\u003e events, which is the log source for this detection.\u003c/li\u003e\n\u003cli\u003eWhen an alert fires, immediately investigate the \u003ccode\u003eaws.cloudtrail.user_identity.arn\u003c/code\u003e and \u003ccode\u003eaws.cloudtrail.resources.account_id\u003c/code\u003e fields to identify the calling principal and the affected member account.\u003c/li\u003e\n\u003cli\u003eExamine \u003ccode\u003esource.address\u003c/code\u003e, \u003ccode\u003esource.geo.*\u003c/code\u003e, and \u003ccode\u003euser_agent.original\u003c/code\u003e fields within the CloudTrail logs to understand the origin of the suspicious \u003ccode\u003eAssumeRoot\u003c/code\u003e call.\u003c/li\u003e\n\u003cli\u003eCorrelate follow-on activity by searching for subsequent events where \u003ccode\u003eaws.cloudtrail.user_identity.access_key_id\u003c/code\u003e matches the temporary credentials issued by the \u003ccode\u003eAssumeRoot\u003c/code\u003e event.\u003c/li\u003e\n\u003cli\u003eRestrict \u003ccode\u003ests:AssumeRoot\u003c/code\u003e usage by applying stringent IAM conditions, such as \u003ccode\u003eaws:PrincipalArn\u003c/code\u003e or \u003ccode\u003eaws:PrincipalOrgID\u003c/code\u003e, to limit which roles and identities can invoke this action.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-07-15T14:27:27Z","date_published":"2026-07-15T14:27:27Z","id":"https://feed.craftedsignal.io/briefs/2026-07-aws-sts-assumeroot-rare-user/","summary":"Adversaries leveraging compromised user credentials can perform a suspicious AWS STS AssumeRoot action by a rarely observed user and member account combination to escalate privileges and gain unauthorized access to AWS resources, potentially leading to data exfiltration or resource manipulation.","title":"Suspicious AWS STS AssumeRoot by Rare User and Member Account","url":"https://feed.craftedsignal.io/briefs/2026-07-aws-sts-assumeroot-rare-user/"}],"language":"en","title":"CraftedSignal Threat Feed - Aws-Sts","version":"https://jsonfeed.org/version/1.1"}