A new documentary series about cybercrime airing next month on HBO Max features interviews with Yours Truly. The four-part series follows the exploits of Julius Kivimäki, a prolific Finnish hacker recently convicted of leaking tens of thousands of patient records from an online psychotherapy practice while attempting to extort the clinic and its patients.
On July 22, 2025, the European police agency Europol said a long-running investigation led by the French Police resulted in the arrest of a 38-year-old administrator of XSS, a Russian-language cybercrime forum with more than 50,000 members. The action has triggered an ongoing frenzy of speculation and panic among XSS denizens about the identity of the unnamed suspect, but the consensus is that he is a pivotal figure in the crime forum scene who goes by the hacker handle “Toha.” Here’s a deep dive on what’s knowable about Toha, and a short stab at who got nabbed.
KrebsOnSecurity recently heard from a reader whose boss’s email account got phished and was used to trick one of the company’s customers into sending a large payment to scammers. An investigation into the attacker’s infrastructure points to a long-running Nigerian cybercrime group that is actively targeting established companies in the transportation and aviation industries.
Authorities in the United Kingdom this week arrested four alleged members of “Scattered Spider,” a prolific data theft and extortion group whose recent victims include multiple airlines and the U.K. retail chain Marks & Spencer.
In May 2025, the U.S. government sanctioned a Chinese national for operating a cloud provider linked to the majority of virtual currency investment scam websites reported to the FBI. But more than a month later, the accused continues to openly operate accounts at a slew of American tech companies, including Facebook, Github, LinkedIn, PayPal and Twitter/X.
Late last year, security researchers made a startling discovery: Kremlin-backed disinformation campaigns were bypassing moderation on social media platforms by leveraging the same malicious advertising technology that powers a sprawling ecosystem of online hucksters and website hackers. A new report on the fallout from that investigation finds this dark ad tech industry is far more resilient and incestuous than previously known.
The U.S. government today imposed economic sanctions on Funnull Technology Inc., a Philippines-based company that provides computer infrastructure for hundreds of thousands of websites involved in virtual currency investment scams, commonly known as “pig butchering.” In January 2025, KrebsOnSecurity detailed how Funnull was being used as a content delivery network that catered to cybercriminals seeking to route their traffic through U.S.-based cloud providers.
Authorities in Pakistan have arrested 21 individuals accused of operating “Heartsender,” a once popular spam and malware dissemination service that operated for more than a decade. The main clientele for HeartSender were organized crime groups that tried to trick victim companies into making payments to a third party, and its alleged proprietors were publicly identified by KrebsOnSecurity in 2021 after they inadvertently infected their computers with malware.
The U.S. government today unsealed criminal charges against 16 individuals accused of operating and selling DanaBot, a prolific strain of information-stealing malware that has been sold on Russian cybercrime forums since 2018. The FBI says a newer version of DanaBot was used for espionage, and that many of the defendants exposed their real-life identities after accidentally infecting their own systems with the malware.
KrebsOnSecurity last week was hit by a near record distributed denial-of-service (DDoS) attack that clocked in at more than 6.3 terabits of data per second (a terabit is one trillion bits of data). The brief attack appears to have been a test run for a massive new Internet of Things (IoT) botnet capable of launching crippling digital assaults that few web destinations can withstand. Read on for more about the botnet, the attack, and the apparent creator of this global menace.
