AT&T Breach Incident Score: Analysis & Impact (ATT1803418111425)

In this Rankiteo incident briefing, we review the AT&T breach identified under incident ID ATT1803418111425.

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 342 and after the incident was 231 with a difference of -111 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 2024 Data Breaches Settlement", a noteworthy cybersecurity incident.

AT&T agreed to pay $177 million to victims of two major 2024 data breaches that exposed sensitive customer data, including Social Security numbers and call records.

The disruption is felt across the environment, affecting AT&T customer databases and Third-party cloud platform (July 2024 breach), and exposing Names, Addresses and Phone numbers, with nearly Millions (exact number unspecified) records at risk, plus an estimated financial loss of $177 million (settlement fund).

In response, teams activated the incident response plan, while recovery efforts such as Settlement fund of $177 million for affected customers continue, and stakeholders are being briefed through Public advisories, official settlement website, media coverage (e.g., Rolling Out, PIX11).

The case underscores how Settlement agreed; final approval hearing scheduled for January 15, 2026. Payments expected to begin distribution in early 2026 after administrative processing, teams are taking away lessons such as The settlement highlights the critical need for stronger data security measures, corporate accountability, and proactive customer protection in the digital age. The scale of the payout underscores the growing legal and financial risks associated with data breaches, particularly when sensitive information like SSNs is exposed, and recommending next steps like Enhance data encryption and access controls, especially for third-party cloud platforms, Implement stricter monitoring for dark web leaks and unauthorized data access and Improve incident response transparency and timeliness in public disclosures, with advisories going out to stakeholders covering Customers advised to file claims by December 18, 2025, via the official settlement website. Options to opt out or object by November 18, 2025, are available for those wishing to pursue individual legal action.

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 Valid Accounts: Cloud Accounts (T1078.004) with moderate to high confidence (85%), supported by evidence indicating third-Party Cloud Platform Exploitation (July 2024) in attack_vector and Phishing: Spearphishing Link (T1566.002) with lower confidence (30%), supported by evidence indicating dark Web Data Leak (March 2024) suggests possible credential harvesting. Under the Collection tactic, the analysis identified Data from Local System (T1005) with high confidence (95%), supported by evidence indicating names, SSNs, call records, account passcodes in data_compromised and Data from Cloud Storage Object: Cloud Storage (T1213.002) with high confidence (90%), supported by evidence indicating third-party cloud platform (July 2024 breach) in systems_affected. Under the Exfiltration tactic, the analysis identified Exfiltration Over Alternative Protocol: Exfiltration Over Unencrypted/Obfuscated Non-C2 Protocol (T1048.003) with high confidence (90%), supported by evidence indicating data appeared on the dark web (March 2024) in data_exfiltration and Exfiltration Over Command and Control Channel (T1041) with moderate to high confidence (70%), supported by evidence indicating call records downloaded in July 2024 implies controlled data transfer. Under the Credential Access tactic, the analysis identified Unsecured Credentials: Credentials In Files (T1552.001) with moderate to high confidence (80%), supported by evidence indicating account passcodes exposed in data_compromised and Credentials from Password Stores: Password Managers (T1555.005) with moderate confidence (60%), supported by evidence indicating third-party cloud platform breach may involve credential stores. Under the Impact tactic, the analysis identified Data Destruction (T1485) with lower confidence (10%), supported by evidence indicating no direct evidence, but data exposure implies potential misuse and Identity Theft (T1659) with high confidence (95%), supported by evidence indicating high identity theft risk (due to SSNs and personal data) in impact. Under the Defense Evasion tactic, the analysis identified Indicator Removal: File Deletion (T1070.004) with lower confidence (40%), supported by evidence indicating no explicit logs mentioned; dark web leak suggests cleanup and Impair Defenses: Disable or Modify Tools (T1562.001) with lower confidence (30%), supported by evidence indicating inadequate protection of sensitive data hints at disabled monitoring. Under the Persistence tactic, the analysis identified Account Manipulation: Additional Cloud Credentials (T1098.003) with moderate to high confidence (70%), supported by evidence indicating third-party cloud platform breach suggests persistent access. These correlations help security teams understand the attack chain and develop appropriate defensive measures based on the observed tactics and techniques.