Mutares SE & Co. KGaA · Breach

Brain Cipher claims attack on Mutares, theft of 105 GB

Nov 06, 2026 · 1 min read

The Brain Cipher ransomware group has listed Mutares, the Munich-based private equity holding listed on the Frankfurt Stock Exchange, on its data-leak site and claims to hold about 105 GB of data. No file list, samples, or confirmation from Mutares exists, and the claim remains unverified. Monitor the group's leak site and official statements until the company or a German authority confirms.

By HIFY Radar newsroom Updated 11/06/2026 07:37 PM Get this every day →← Back to the feed 1 source

MediumBreachNo software to update

In this article

What happened
Why it matters
What to do
For the technical team
Timeline
Sources

What happened

The Brain Cipher ransomware group has listed Mutares, the Munich-based private equity holding listed on the Frankfurt Stock Exchange, on its data-leak site. The group claims to hold about 105 GB of data. Mutares has not confirmed an incident, and no file list or samples exist.

Why it matters

Mutares holds dozens of portfolio companies across automotive, energy, infrastructure/defense, goods, and chemicals. A real compromise of the holding, if confirmed, could expose deal files, portfolio financials, and personal data spanning many operating businesses, per DailyDarkWeb.

What to do

Treat the claim as unverified until Mutares or a German authority confirms. Review your company's exposure to Mutares and its portfolio companies. Monitor the group's leak site and official statements.

For the technical team

Affected: Mutares SE & Co. KGaA (mutares.com), holding de private equity sediada em Munique e listada na bolsa de Frankfurt · Mutares SE & Co. KGaA (mutares.com), Munich-based private equity holding listed on the Frankfurt Stock Exchange (SDAX, ticker MUX)
Exploitation: Claim by the Brain Cipher ransomware group, which listed the victim on its data-leak site with about 105 GB of data. No file list, categories, or samples verified. Unverified claim; Mutares has not publicly confirmed an incident.
Fix: No software to update
More details: Brain Cipher uses LockBit Black-derived tooling and routinely posts mid-market victims, per DailyDarkWeb. Mutares is a special-situations investor listed on the SDAX, with dozens of portfolio companies across automotive, energy, infrastructure/defense, goods, and chemicals.