The Cleus Blog
Tutorials, engineering deep-dives, and product updates on building with AI agents — research, coding, images, video and voice.
What to Do After a Data Breach: Check If You Were Leaked and Lock Down Your Accounts
Your details were in a data breach. Here is how to check what leaked, the seven steps that lock your accounts down, how credit freezes work in the US, UK, EU and Japan, and what criminals can do with each kind of data.
Bybit Hack Explained: How North Korea Stole $1.5 Billion From Bybit
On February 21, 2025, Bybit lost about $1.5 billion in ETH without a single private key leaking. How a hacked Safe{Wallet} laptop and a lying screen did it, how Bybit survived, and how little was ever recovered.
Lazarus Group and TraderTraitor: North Korea’s Crypto Hackers Explained
Who the Lazarus Group and TraderTraitor really are, the crypto heists the FBI and analytics firms have pinned on them, the lures they use, why North Korea does it, and how to defend against them.
The Biggest Crypto Hacks in History: 17 Heists Ranked (2026 Update)
From Mt. Gox to Binance's $6.36 billion theft: the 17 largest crypto heists ever, what each was worth when stolen, how attackers got in, how much came back, and how to protect your own coins.
KDDI Data Breach Explained: How a Zero-Day Exposed 12 Million ISP Email Accounts
A zero-day in third-party software let attackers into the email platform KDDI runs for six Japanese ISPs. Who was hit, what leaked, what regulators did and what to do now.
Japan Data Breaches, October 2026: Rakuten Travel, Furusato Choice and a Month of Leaks
Furusato Choice, Rakuten Travel, Sony's So-net, Capcom, Sourcenext, Burger King Japan: October 2026 brought so many leaks that Japan's prime minister called an emergency ministers' meeting. What each one exposed, why Japan is being hit, and what to do.
Polymarket Hacked: How a Hijacked DebugBear Script Drained About $2.7M From Traders
On October 29, a hijacked website-monitoring script hit Polymarket's international site, sold traders' positions and moved out roughly $2.7 million. The timeline, how it worked, the refund rules and what to do now.
Sony Data Breach 2026: How Hackers Took 2.58 Million So-net and plala Records
An outsider broke into Sony's So-net member database on October 19 and took up to 2.58 million customer records, plus 54,401 email passwords. Here's the timeline, exactly what leaked, and what to do now.