AT&T Breach Incident Score: Analysis & Impact (ATT3033030111925)

In this Rankiteo incident briefing, we review the AT&T breach identified under incident ID ATT3033030111925.

The analysis begins with a detailed overview of AT&T's information like the linkedin page: https://www.linkedin.com/company/att, the number of followers: 1591781, the industry type: Telecommunications and the number of employees: 177538 employees

After the initial compromise, the video explains how Rankiteo's incident engine converts technical details into a normalized incident score. The incident score before the incident was 429 and after the incident was 366 with a difference of -63 which is could be a good indicator of the severity and impact of the incident.

In the next step of the video, we will analyze in more details the incident and the impact it had on AT&T and their customers.

AT&T recently reported "AT&T Data Breaches (March & July 2024)", a noteworthy cybersecurity incident.

AT&T suffered two major data breaches in 2024, exposing personal and call-related data of millions of customers.

The disruption is felt across the environment, affecting Third-party cloud platform, and exposing Phone numbers, Addresses and Email addresses, with nearly Millions records at risk, plus an estimated financial loss of $177 million (settlement).

In response, teams activated the incident response plan, and stakeholders are being briefed through Customer notifications began in July 2024.

The case underscores how Completed (settlement pending final court approval on 2026-01-15), teams are taking away lessons such as Importance of securing third-party cloud platforms, timely customer notification, and proactive legal settlement to avoid prolonged litigation, and recommending next steps like Enhance third-party vendor security assessments, Implement stricter access controls for cloud-stored data and Improve incident response timelines for public disclosure, with advisories going out to stakeholders covering Customers notified via direct communication; settlement claims process established (deadline: 2024-12-18).

Finally, we try to match the incident with the MITRE ATT&CK framework to see if there is any correlation between the incident and the MITRE ATT&CK framework.

The MITRE ATT&CK framework is a knowledge base of techniques and sub-techniques that are used to describe the tactics and procedures of cyber adversaries. It is a powerful tool for understanding the threat landscape and for developing effective defense strategies.

Rankiteo's analysis has identified several MITRE ATT&CK tactics and techniques associated with this incident, each with varying levels of confidence based on available evidence. Under the Initial Access tactic, the analysis identified Trusted Relationship (T1199) with high confidence (95%), with evidence including third-party cloud platform compromise (attack_vector), and entry point such as Third-party cloud platform. Under the Collection tactic, the analysis identified Data from Local System (T1005) with high confidence (95%), with evidence including data from cloud platform such as PII, SSNs, call records, account passcodes (data_breach.type_of_data_compromised), and illegal downloads from a third-party cloud platform. Under the Exfiltration tactic, the analysis identified Exfiltration Over Alternative Protocol: Exfiltration Over Unencrypted/Obfuscated Non-C2 Protocol (T1048.003) with moderate to high confidence (85%), with evidence including illegal downloads from a third-party cloud platform (implied bulk data transfer), and data exfiltration such as Yes. Under the Impact tactic, the analysis identified Data Destruction (T1485) with lower confidence (10%), supported by evidence indicating no explicit destruction mentioned, but data exposed for identity theft (low confidence), Data Encrypted for Impact (T1486) with lower confidence (5%), supported by evidence indicating no ransomware mentioned; included for completeness only, and Identity Theft (T1659) with high confidence (95%), with evidence including identity theft risk such as High (SSNs and personal data exposed), and enabling potential identity theft and financial fraud. Under the Credential Access tactic, the analysis identified Unsecured Credentials: Credentials In Files (T1552.001) with high confidence (90%), with evidence including account passcodes exposed in breach (data_breach.personally_identifiable_information), and third-party cloud platform likely stored credentials in files. Under the Defense Evasion tactic, the analysis identified Indicator Removal: File Deletion (T1070.004) with lower confidence (30%), supported by evidence indicating no direct evidence, but delayed detection (March/July breach detected in April) suggests possible log tampering and Impair Defenses: Disable or Modify Cloud Logs (T1562.001) with lower confidence (40%), with evidence including delayed detection (4+ months for July breach) implies possible cloud logging evasion, and inadequate security controls on third-party cloud platform. These correlations help security teams understand the attack chain and develop appropriate defensive measures based on the observed tactics and techniques.