The notorious Scattered Spider hacking group has claimed responsibility for a massive breach, stealing six terabytes of sensitive data from the formidable digital fortresses of MGM Resorts International and Caesars Entertainment.

Caesars and MGM have yet to acknowledge the magnitude of the data compromised officially.

As both corporate giants scramble to assess the extent of the damage, cybersecurity experts and law enforcement agencies are grappling with the far-reaching implications of the heist.

Scattered Spider, aka UNC3944, has long been a thorn in the side of American cybersecurity. Characterised by its audacious social engineering tactics, the group has consistently outwitted even the most vigilant security measures.

Reaching out to Reuters via Telegram, a spokesperson for Scattered Spider remained cryptic about their intentions. Although they admitted to the breach, the group remained tight-lipped about whether they intended to publish the stolen data or had initiated ransom negotiations with the beleaguered companies.

The contact information for Scattered Spider was discreetly provided to Reuters by an anonymous cybersecurity expert, the curator of an online repository known as ‘vx-underground’.

Caesars Entertainment, a corporate giant in the casino industry, disclosed to regulators that on September 7, hackers successfully accessed sensitive information of a substantial number of its loyalty programme members, including potentially compromising data like “driver’s licence numbers and/or Social Security numbers.”

Operations within MGM Resorts International’s sprawling Las Vegas casinos remain disrupted four days after the initial revelation, with social media posts displaying slot machines flashing ominous error messages.

Scattered Spider’s reign of cyberterror has not been limited to these two corporate giants.

According to Mandiant Intelligence, a subsidiary of Google, the hacking group has orchestrated over 100 intrusions in the past two years across various industries, spanning gaming, technology, retail, telecom, and insurance sectors.

Charles Carmakal, chief technology officer at Mandiant, revealed that the group’s members appear to be dispersed across several Western countries, adding a layer of complexity to the ongoing investigations.

Caesars Entertainment said the breach’s origins allegedly resulted from a “social engineering attack” targeting an IT vendor with whom the company had established a relationship.