A suspected ransomware affiliate is posing as a ransomware recovery service called "Ransom Busters," contacting victims before the attacks become public and claiming it can provide decryption keys and delete stolen data for a fee. GuidePoint Security's Research and Intelligence Team (GRIT) disclosed this activity after responding to several recent ransomware attacks in which victims received emails from Ransom Busters offering to help recover from the attack. The messages were suspicious because they were sent to victims before the attacks became public, raising questions about how they knew about the cyberattacks in the first place. Ransom Busters claimed it exploited vulnerabilities in administrative panels used by ransomware-as-a-service (RaaS) operations, giving it access to encryption keys and data stolen from victims.
A suspected ransomware affiliate is posing as a ransomware recovery service called "Ransom Busters," contacting victims before the attacks become public and claiming it can provide decryption keys and delete stolen data for a fee. GuidePoint Security's Research and Intelligence Team (GRIT) disclosed this activity after responding to several recent ransomware attacks in which victims received emails from Ransom Busters offering to help recover from the attack. The messages were suspicious because they were sent to victims before the attacks became public, raising questions about how they knew about the cyberattacks in the first place. Ransom Busters claimed it exploited vulnerabilities in administrative panels used by ransomware-as-a-service (RaaS) operations, giving it access to encryption keys and data stolen from victims.
Japanese cloud and data center service provider Sakura Internet disclosed that hackers accessed its sales management system, where customer contract and membership information is stored. In an update today to the initial notification from Monday, the company says the incident may have impacted up to 1,360,563 member accounts. However, as the investigation continues, the exact number of affected accounts remains to be determined. Sakura Internet is a major Japanese digital infrastructure company providing web hosting, VPS, public cloud, data-center, and GPU computing services. It has been selected as a domestic provider for Japan’s Government Cloud program, making it a strategic entity in the country that reduces dependence on foreign hyperscalers. According to the firm’s announcement, hackers accessed its IT system on August 9. The incident was discovered later during the investigation of a separate breach at the Sakura Rental Server service.
U.S. healthcare IT company CareCloud disclosed that the data breach incident it suffered earlier this year has impacted more than 3.7 million individuals. The healthcare technology organization is publicly traded and provides electronic health records, medical billing, practice management, and revenue-cycle services. The company disclosed the incident in March via a filing with the U.S. Securities and Exchange Commission (SEC), noting that the attack caused an 8-hour network disruption on its platform and cut access to one of its databases. At the time, the firm said the compromised environment contained patient data, indicating the risk of sensitive medical information being stolen. Following the incident, CareCloud launched an investigation to determine its scope and how many people were potentially impacted.
In a large-scale campaign that researchers dubbed CameraSwarm, hackers compromised more than 14,500 Dahua IP cameras mostly in Ukraine and Russia. The operation ran for at least 35 days between June 17 and July 22, compromising devices by exploiting vulnerabilities, brute-forcing logins, and using offline recovery codes from serial numbers for cloud-registered cameras. Researchers at threat intelligence company Hunt.io discovered the campaign after finding a working directory on an HTTP server that the operator left unprotected. Hunt.io recovered 407 MB of data comprising 2,616 files across 234 directories, including source code, logs, credentials, captured camera images, shell history, and exploitation results, which helped them map an impressive operation. According to their findings, the 35-day CameraSwarm campaign compromised 14,530 Dahua IP cameras using three attack methods in parallel:
U.S. cybersecurity agencies warn that threat actors are using AI-generated scripts to exploit Siemens S7 Series programmable logic controllers (PLCs) in U.S. critical infrastructure. PLCs are industrial computers used to automate and control machinery and physical processes in factories and other critical infrastructure. The NSA, CISA, FBI, Department of Energy, and Environmental Protection Agency issued the joint advisory Wednesday, saying the attacks are ongoing. "This advisory relates to an active threat to Siemens S7 Series programmable logic controllers (PLCs)," reads the advisory. "However, ongoing PLC targeting activity is broader than Siemens PLCs. All PLC owners and operators should apply relevant mitigations to reduce the risk to their devices and systems." The critical infrastructure sectors most targeted include Critical Manufacturing, Energy, Water and Wastewater Systems, Chemical, Food and Agriculture, and Commercial Facilities. The agencies also note that Siemens S7 PLCs are used in the Defense Industrial Base, which could also be targeted.
Microsoft tracked over 30 MacSync Stealer domains by focusing on behavioral patterns, revealing a campaign targeting passwords, keys, wallets and other data. Domain blocking is a losing game when the thing you’re blocking can register a new domain faster than you can add it to a list. That’s the exact problem Microsoft Defender Experts ran into while tracking MacSync Stealer, a macOS-focused information stealer that RST Cloud first flagged for swapping out its command-and-control infrastructure almost immediately after getting publicly outed. Microsoft detailed how its experts stopped chasing individual domains and started tracking the behaviors that stayed constant underneath them. Instead of tracking individual domains, Microsoft looked at recurring request patterns, HTTP headers and other behaviors. This allowed its researchers to link more than 30 domains to the same campaign and determine that the infrastructure was doing more than just sending commands to infected Macs. It was also being used to collect, stage and exfiltrate stolen data. “MacSync Stealer is a macOS-focused information stealer that relies on changing infrastructure to deliver payloads, communicate with compromised devices, and exfiltrate data. Earlier reporting by RST Cloud identified the threat through a limited set of domains and documented rapid command-and-control (C2) replacement after public disclosure.” reads the report published by Microsoft. “Microsoft Defender Experts expanded that view by correlating recurring endpoints and network behaviors across the activity. This behavior-led approach connected more than 30 domains and showed that the infrastructure supported more than C2 communication, extending into active collection, staging, and exfiltration.” The infection chain starts with a trick rather than an exploit. Victims get social-engineered through a technique known as ClickFix, tricked into pasting or running commands directly in macOS Terminal, and once that shell session fires, curl pulls down attacker-controlled payload content from a path formatted as /curl/[token]. Then, native macOS tools decode and unpack the payload, and an AppleScript-driven layer takes over, blending Unix commands like sh, cp, rm, and killall with osascript calls that make the whole chain look more like ordinary system scripting than malware. Once active, the stealer focuses on valuable data. The malicious code looks for macOS Keychain data, saved browser passwords and cookies, SSH keys, AWS credentials, Kubernetes configurations and files in common user folders. It also searches for Ledger and Trezor wallet data, showing that the malware targets users with valuable credentials and assets rather than simply collecting random browser history. What actually confirms exfiltration, rather than just suspicious traffic, is the upload mechanism itself. Collected data gets staged under temporary paths, compressed into an archive, split into chunks, and pushed out through HTTP PUT requests carrying parameters like upload_id, chunk_index, and total_chunks. “The staged archive was uploaded through rotating infrastructure using curl and HTTP PUT requests. Observed requests included –data-binary, API-key headers, macOS User-Agent string, upload_id values, chunk_index values, and total_chunks parameters.” states Microsoft. “These upload traits confirmed active data exfiltration and provided durable hunting pivots even when domains rotated. “ The researchers pointed out that the exfiltration method stays recognizable even when the destination keeps changing. RST Cloud’s follow-up work backs up how consistent this infrastructure actually is under the surface. Using the same recurring URI patterns, RST Cloud surfaced eleven additional candidate domains and found a static API-key value shared across four confirmed command-and-control domains, even while the build token attached to each deployment kept rotating. A shared static key sitting inside otherwise rotating infrastructure is exactly the kind of detail that makes automated evasion look less impressive up close. The attack wraps up with cleanup, deleting temporary archives, staging folders, and lock files after the upload completes. Microsoft notes this reduces what’s left sitting on disk, but it doesn’t erase the behavioral sequence itself. “After exfiltration, the malware removed temporary archives, staging folders, lock files, and other artifacts. Although this cleanup reduced on-disk evidence, the sequence of archive creation, chunked upload, and deletion can still provide a useful behavioral correlation for defenders.” concludes Microsoft. For anyone defending Mac fleets, the practical takeaway here isn’t a list of domains to block, since that list will be stale within days. It’s building detection around the recurring shape of the attack itself: shell sessions spawning curl with those specific flag patterns, osascript chaining rapidly into network activity, and archives appearing under /tmp/sync* right before outbound PUT traffic starts. Chase the pattern, not the address, because the address was never going to sit still long enough to matter. Follow me on Twitter: @securityaffairs and Facebook and Mastodon Pierluigi Paganini (SecurityAffairs – hacking, malware)
Over 50,000 exposed Stripe API keys show how leaked secrets can enable fraud, data access and account abuse within hours. Ransomnews researchers have documented a large-scale leak of Stripe merchant API keys found exposed in public code repositories, GitHub Actions logs, and misconfigured web servers, with over 50,000 unique keys identified in total. The research is practical rather than theoretical: the team tested a sample of the keys, found a meaningful portion still active, and documented exactly how quickly a fraudster could exploit them. The answer is fast. “A dataset published on a data-trading forum on 18 August 2026 contains live Stripe API keys for 659 merchant accounts, along with roughly 35 GB of customer and payment data pulled from them.” reads the report published by Ransomnews. “Ransomnews analysed the files offline and reported the exposure to Stripe before publishing. Stripe itself was not compromised. The keys belong to merchants.” Researchers said that after finding an active Stripe API key, they were able to access a merchant’s customer list, create a fraudulent payment link and make a $1 test charge within 17 hours. The key alone was enough to perform these actions, highlighting the risks of exposed credentials and insufficient API protections. The operations a live Stripe secret key unlocks are extensive: listing customers and their stored payment methods, creating charges and payment intents, issuing refunds to attacker-controlled accounts, modifying webhook endpoints to intercept future payment notifications, and in some cases accessing connected accounts if the merchant had enabled Stripe Connect. A secret key is not a partial credential. It’s full API access. The sources of the leaked keys are unsurprising to anyone who has done developer security work. GitHub repositories — both public and accidentally made public, account for the largest share, typically through hardcoded keys in configuration files, .env files committed without a corresponding .gitignore entry, or keys left in code comments. GitHub Actions build logs are the second major source: when a workflow prints environment variables for debugging, any secret that wasn’t properly masked ends up in a log that anyone with repository access can read. Misconfigured web servers are another major source of exposed Stripe API keys. Researchers found over 3,000 servers revealing Stripe-related strings, with about 12% containing keys that worked against the Stripe API. The source of the 659 exposed merchant keys is unclear, but likely includes infostealer logs, public repositories, exposed environment files and misconfigured backups. The collector’s real advantage was systematically validating the keys, accessing each account and organizing the stolen data. “The dataset doesn’t say, and we are not going to guess at a single source for 659 separate merchants. The realistic candidates are the ordinary ones: secret keys sitting in infostealer logs lifted from developer machines, keys committed to public repositories, keys left in exposed environment files, keys pulled out of misconfigured backups. Stripe’s own documentation says the company scans for exactly this, and describes finding merchant keys on repositories and package registries.” concludes the report. “What the collector added was patience. Gathering keys is common. Validating several hundred of them, then systematically walking the API for each account and archiving the results into a consistent folder structure, is a different level of effort.” Stripe does provide automatic secret scanning through GitHub’s partner program, which flags Stripe keys found in public repositories and can trigger automatic revocation when a merchant opts in. The problem is that opt-in rate is low, the scanning doesn’t cover private repositories, and it has no coverage over build logs, web server misconfigurations, or other platforms where keys surface. Ransomnews also found that some merchants had rotated their keys after a GitHub exposure but left the old keys active, possibly because Stripe doesn’t revoke keys on rotation unless you explicitly delete the old one. The remediation is not complicated. Audit your current Stripe keys against your version control history to see if any have ever been committed. Rotate any key that has touched a public repository, a build log, or a configuration file that wasn’t explicitly protected. Enable Stripe’s restricted keys for any integration that doesn’t need full account access — a webhook handler doesn’t need the ability to create charges. And enable Stripe Radar rules to flag unusual charge patterns that might indicate someone else is using your key before you’ve noticed it’s gone. Follow me on Twitter: @securityaffairs and Facebook and Mastodon Pierluigi Paganini (SecurityAffairs – hacking, data leak)
The Cybersecurity and Infrastructure Security Agency (CISA) said Tuesday that the Medusa ransomware gang has breached more than 500 critical infrastructure organizations in the United States since June 2021. This was revealed in a joint advisory in coordination with the Department of Health and Human Services (HHS) and the Federal Bureau of Investigation (FBI). "As of April 2026, Medusa actors have impacted more than 500 victims across multiple critical infrastructure sectors, including Healthcare and Public Health, Defense Industrial Base, Critical Manufacturing, Government Services and Facilities, Information Technology, and Financial Services," they said. "Other victims include organizations in the medical, education, legal, insurance, technology, and manufacturing industries." This is an update to a joint report published in March 2025, which said the Medusa ransomware operation had impacted an estimated over 300 critical infrastructure organizations.
Most email defenses still do the job they did a decade ago. Scan the message, look for something malicious, block it. That worked when the danger sat in the payload, a bad link or an attachment. It stopped working when the danger moved into the message's intent, and it is failing now that the sender is no longer a person. From Bad Content to Bad Intent to AI on Both Sides Phishing 1.0 was bad
Confirm this action.
Leaving now will discard your changes.