MGM Resorts International September 2023 Ransomware Attack

Incident Name: MGM Resorts International September 2023 Ransomware Attack

Date of Incident: September 10th, 2023


On September 11th, 2023, MGM Resorts International announced that they are currently dealing with a cyber attack that is impacting their company’s systems and all 31 of their resorts, many of which are located in Las Vegas. Numerous systems are currently offline, including the main website, casino floor machines and services, reservations, and the MGM Rewards app. Customers have been instructed to contact each hotel directly using their phone numbers to address MGM rewards-related issues. As a result of this attack, customers are experiencing long queues, difficulties accessing hotel rooms, and disruptions in the casinos across all the resort hotels in Las Vegas.

This incident is believed to be a ransomware attack. On September 12th, malware researchers from vx-underground revealed on X (previously Twitter) that the ALPHV ransomware group was responsible for this cyber attack. The threat actors allegedly obtained employee information from LinkedIn and then exploited helpdesk personnel through social engineering techniques to gain unauthorized access to MGM systems. It is worth noting that MGM has not confirmed these details or disclosed any plans regarding the ransom payment. Furthermore, as of now, MGM has not appeared on the ALPHV leak site.

There have been unverified reports on social media suggesting that Caesars Palace in Las Vegas experienced a ransomware attack the week before and paid the ransom. However, the hotel has not officially confirmed these claims. As of September 12th, 2023, MGM has announced partial restoration of some systems. Given that this situation is still evolving, further updates will be provided in due course.

It seems that targeting helpdesk employees, who typically possess elevated privileges, is becoming an increasingly popular approach for threat actors to infiltrate organizations through social engineering. Recently, Okta, a provider of identity and authentication services, issued a warning to its customers about an ongoing and sophisticated social engineering attack targeting IT service desk employees. Beginning in August 2023, multiple Okta customers reported falling victim to these attacks, which leveraged a technique known as vishing to deceive employees.

Key Social Engineering/OSINT Themes:

  • Recon – MGM employee and organizational information was harvested via LinkedIn (allegedly). The threat actor leveraged exposed employee information to conduct a social engineering attack.
  • Vishing – The threat actor targeted IT Help Desk personnel with high privileges with the purpose of gaining access.

Picnic’s Recommended Remediations:
For detailed remediations, see the HASP Framework.

High Risk Employees

  • HASP Framework 1.1 — Identify high-value employee targets
  • HASP Framework 1.3 — Conduct social engineering risk assessments for high-value employee targets
  • HASP Framework 1.5 — Establish and implement procedures for high-value employee targets
  • HASP Framework 1.7 — Increase detection and monitoring for high-value employee targets

Exposed Employee PII

  • HASP Framework 2.1 — Identify exposed employee PII
  • HASP Framework 2.2 — Reduce exposed employee PII

Exposed Credentials

  • HASP Framework 3.1 — Identify exposed work credentials
  • HASP Framework 3.7 — Restrict service account access
  • HASP Framework 3.8 — Monitor for account takeover (including real-time alerts on exposed credentials)
  • HASP Framework 3.9 — Monitor for MFA configuration changes
  • HASP Framework 3.10 — Monitor for new MFA registrations

Exposed Remote Services

  • HASP Framework 4.2 — Identify exposed shadow IT
  • HASP Framework 4.4 — Manage shadow IT / remote access

Indicators of Attack

  • HASP Framework 7.1 — Monitor for suspicious external accounts
  • HASP Framework 7.2 — Request takedowns for suspicious external accounts
  • HASP Framework 7.3 — Alert your organization about suspicious external accounts
  • HASP Framework 7.4 — Monitor for suspicious domains
  • HASP Framework 7.5 — Block suspicious domains

Cyber Awareness

  • HASP Framework 8.1 — Train employees on social engineering attacks
  • HASP Framework 8.2 — Provide employees with social engineering phishing simulation training
  • HASP Framework 8.4 — Build and establish social engineering policies, processes, and procedures

Industry: Financial Services, Professional Services

Actor: Suspected to be ALPHV ransomware group

Motivations: Financial

Related Hacks: Marriott (2022) / IHG (2022), Luna Hotels & Resorts (2023)

Breach Notice/Company Notice:

Other Sources:

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