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Received — 5 June 2026 The Register - Security

If you don't fall for these extortionists' calls, they'll show up with USB sticks

5 June 2026 at 21:18
If they don't get you online, they'll try in person. A data-theft and extortion gang has targeted “dozens” of banks, law firms, and other professional services companies in the US from January through May, using fake help desk calls and other social-engineering techniques to gain access to corporate IT environments, according to Google’s Mandiant incident response team. And when those remote-deception methods don’t work, the criminals sometimes show up at victims’ physical offices, posing as IT technicians, and attempt to steal sensitive files using thumb drives. Google’s threat hunters track the extortion threat group as UNC3753, while other analysts call it Luna Moth, Chatty Spider, and Silent Ransom Group. The crew has been around since 2022, originally using fake software renewal emails and other billing lures, typically with PDF attachments containing phone numbers for attacker-controlled call centers, as their means of gaining initial access to corporate networks. Beginning around March 2025, the crims shifted tactics and started posing as IT help desk staff. “While UNC3753 primarily relies on digital vectors, GTIG assesses that associated threat actors have also attempted direct data theft using physical, in person access,” Google incident responders and researchers Chad Reams, Tufail Ahmed, Keith Knapp, Ashley Frazer, and Tyler McLellan said in a Friday blog. The authors also pointed to a May FBI alert to corroborate this in-person tactic. According to the feds, Silent Ransom Group crooks have been walking into law firms’ physical offices as recently as this spring. Once they are on-site, they claim to be IT support staff needing to image a device or create local backups for security reasons. If that line works, they plug a thumb drive into the victim’s computer and steal data the old-fashioned way. “Although limited forensic evidence and the absence of a subsequent extortion attempt prevent formal attribution, GTIG assesses that these physical intrusions are likely associated with UNC3753 based on structural, timeline, and targeting overlaps,” the blog said. Google won’t say how many dozens of firms have been targeted in these attacks, or how many ended in the data thieves paying a visit to the victims’ locations. “While we can’t share additional details regarding specific investigations, Mandiant CTO Charles Carmakal notes that this tactic has been observed over the years,” a spokesperson told The Register. “Mandiant has investigated various matters where adversaries planted insiders, bribed employees, or physically entered buildings to facilitate cyberattacks.” Another noteworthy thing about UNC3753’s attacks: they are very fast. In many of Mandiant’s investigated incidents, the entire operation from initial contact to data extortion occurred in just one day. “Recently, Mandiant observed data searches, staging, and theft initiated in under an hour,” the threat analysts warned. These intrusions typically begin with an invoice-themed email - but these don’t usually contain any malicious links or attachments. The email’s sole purpose is to give the miscreants a plausible reason to follow up via phone, so that the recipient is more likely to believe the call is legitimate. Most of the crew’s entry mechanisms involve voice-phishing, using a method that has worked so well for other groups like ShinyHunters and Scattered Spider over the past few years. UNC3753 calls organizations’ employees directly and purports to be a help desk worker or member of the security team. The criminals say they need the target’s help addressing a security issue or aiding with a corporate data migration project, and convince the individual to join a screen-sharing session via Zoom, Microsoft Terminal Services, Microsoft Teams, or Quick Assist. In one such intrusion, using Teams to gain access to the victim’s computer, the attacker jumped on five separate calls with the same target over a three-day period, we’re told. And in more than one incident that Mandiant responded to, UNC3753 established Zoom sessions directly on targets' personal laptops, using these machines to access corporate virtual desktop infrastructure (VDI) using native client platforms, such as Windows 365 or Citrix clients. Once they’re in the corporate systems, the intruders map local directories and network drives, and target specific legal and document storage repositories. The crooks also use very-specific keyword searches to find sensitive folders containing tax logs (Forms W-2, W-9, and 1099), audit files, corporate client agreements, and Social Security numbers, before staging this data for exfiltration. UNC3753 uses several methods to sneak the data out of the corporate IT environment without setting off any security alarm bells, including using portable versions of free Windows file manager WinSCP or another open source filesystem like Rclone. The crew has also been known to log into a file-sharing account from the victim’s browser and upload the stolen files that way - or even instruct the victims to send the files to an attacker-controlled email address. After stealing the data, they send the extortion email, usually within 30 minutes of exiting the victim’s environment, and set a three-day deadline to respond and begin the negotiation process. “We hope to find a financial solution that will be acceptable for both parties,” reads one such extortion email. It continues: In case of ignorance or no agreement, We will notify your employees, partners and customers, after which We will publish your data. You will receive claims from individuals, and legal entities for information leakage and breach of contracts, your current deals will be terminated. Journalists and others will dig into your documents, finding inconsistencies or violations in them. Your organization will lose its reputation, shares will fall in price, and your organization will be forced to close. Stay safe, friends In the Friday report, Google’s threat hunters list IP addresses and other indicators of compromise, including these phishing domains that UNC3753 uses in its social-engineering attacks, all designed to look like the target organization’s help desk: -itdesk[.]com, -it[.]com, and -helpdesk[.]com. The security shop also suggests a range of things companies can do to avoid falling victim to this group and other voice-phishing scams or physical office intrusions. Some of the physical controls include requiring visitors to display official credentials and photo identification, and mandating front-desk staff log all visitor IDs before granting access. Also, check pre-scheduled work orders to ensure the “technician” at the front desk is who they say they are, and make sure any visiting technical service workers are always accompanied by a corporate, in-office supervisor. Because the bulk of these intrusions occur without any physical entry into the office, however, companies should also implement remote access conditional access policies to ensure only corporate-owned devices can authenticate to any VDIs or VPNs. Plus, block the installation and execution of unauthorized remote monitoring and support utilities. ®

Yet another Cisco SD-WAN 0-day under attack, and no patch in sight

5 June 2026 at 17:27
The threat is real. Unknown miscreants are exploiting a high-severity, zero-day bug in Cisco’s SD-WAN management software, and the networking giant hasn’t said when it will patch the flaw. Cisco issued an advisory on Thursday for the Catalyst SD-WAN Manager vulnerability, tracked as CVE-2026-20245, and it sounds like attackers have been exploiting this security failure for at least the last week. It’s due to a validation error - the software fails to properly validate user-supplied input - and an authenticated, local attacker can exploit the flaw by uploading a specially crafted file to vulnerable systems. From there, they can escalate privileges and execute commands with root privileges. The vulnerability affects all versions of the SD-WAN software, regardless of device configuration, and across all deployment types including on-premises, cloud-based, and FedRAMP-certified deployments. Switchzilla says it became aware of attacks against this vulnerability in June. “To exploit this vulnerability, an attacker must have netadmin privileges on an affected system,” the vendor said. “This would require valid credentials or exploitation of CVE-2026-20182 or CVE-2026-20127. Cisco is not aware of successful exploitation by other methods.” Both of these earlier SD-WAN security holes have also been hit by attackers in previous months. The good news: an attacker needs valid credentials to abuse the new hole. The bad news: exposed credentials aren’t hard to find (or buy) online. We don’t know the scope of exploitation or exactly when attackers began hitting this SD-WAN hole. Cisco declined to answer The Register’s questions, and instead sent us a statement via email. “Cisco recommends customers upgrade to the fixed software released in May 2026 for CVE-2026-20182 as a protective measure,” a spokesperson said. “A patch for this vulnerability will be provided on a future date. Customers needing assistance should contact Cisco TAC.” This latest bug is the sixth SD-WAN vulnerability listed as under attack since the start of the year, and the second zero-day in two months. The most recent is the one the Cisco spokesperson mentioned in an email to The Register. In May, Switchzilla disclosed a max-severity make-me-admin bug (CVE-2026-20182) affecting Catalyst SD-WAN Controller and Manager, and warned that attackers had already found and exploited the hole before it issued a patch. A month earlier, America's lead cyber-defense agency said that three Cisco Catalyst SD-WAN Manager bugs (CVE-2026-20128, CVE-2026-20133, and CVE-2026-20122) were under attack, and gave federal agencies just four days to patch the security holes. Cisco fixed all three CVEs in late February, and in March warned of attackers abusing two of them. Also in February, the networking vendor patched a max-severity improper authentication flaw (CVE-2026-20127) affecting the same SD-WAN software, prompting a Five Eyes countries’ joint intelligence alert urgently warning defenders to patch it - plus an old SD-WAN vulnerability (CVE-2022-20775) - or risk root takeover. "Malicious cyber threat actors are targeting Cisco Catalyst SD-WAN used by organizations globally," the UK's lead cyber agency said at the time. "These actors are compromising SD-WANs to add a malicious rogue peer and then conduct a range of follow-on actions to achieve root access and maintain persistent access to the SD-WAN." And while this one isn't listed as under active exploitation (yet), on Wednesday, Cisco warned about a proof-of-concept exploit for CVE-2026-20230, a critical bug in its Unified Communications Manager that also allows attackers to gain root privileges. ®

World Food Programme breach exposes data of 600k vulnerable Gazan families

5 June 2026 at 13:00
Humanitarian organization World Food Programme (WFP) says one of its systems was breached, and around 600,000 Gazan households receiving aid had their details improperly accessed. Its announcement, made via Telegram on May 31, confirmed there was “a security incident” in the self-registration application used by Gazans to register for aid and applicants’ names, ID numbers, phone numbers, and location information were among the data types accessed. “We understand this may be concerning, and we want to assure you that protecting your data and privacy is our top priority,” the WFP said. “The program is treating this situation with the utmost seriousness and priority.” The organization said it temporarily suspended the registration platform to urgently apply the necessary security improvements. Its most recent update on the situation came on June 2, when it said the platform was still down, but added that aid recipients did not need to do anything, while their support would continue to be delivered uninterrupted. “The WFP wants to assure all those registered via the link that food assistance, cash assistance, nutritional supplementation, and all other WFP programs are continuing as usual,” it said. “If you are already registered on the Self-Registration Application (SRA), your registration remains valid. There is no need to update, delete, or re-register your information at this time.” WFP told The New Humanitarian, which first reported the story, that the attack was detected on May 14, and confirmed the scale to be in the region of 600,000 households. The news organization also claimed, citing a whistleblower’s account of matters, that an anonymous “independent expert” contacted WFP’s Palestine team, alerting it to vulnerabilities in the SRA two days before the organization detected the breach. The Register contacted WFP’s Rome headquarters for more details, but it did not immediately respond. WFP, which is a division of the UN and the largest welfare organization in the world, supports 1.6 million Palestinians every month who face a malnutrition crisis amid fierce conflict between the territory and neighboring Israel. This represents around 77 percent of the country’s population, and an estimated 80 percent of the population is unemployed, unable to earn the money required to pay for a nutritionally sound diet. WFP delivers wheat flour, high-energy biscuits, and fortified snacks to families, community kitchens, and bakeries in its effort to push back famine, as well as facilitating cash transfers. The organization is also helping individuals get back into paid work, maintains roads, and says that when conditions allow, it will stay in the region and help local people rebuild communities, markets, and other food systems. ®

Council in UK's City of York outs hundreds of disabled residents with a single email blunder

5 June 2026 at 10:00
A City of York Council email mishap exposed the email addresses of hundreds of Blue Badge holders in the ancient Viking capital, inadvertently revealing their status as disabled residents and triggering a data breach investigation. The council confirmed to The Register that it’s investigating what it described as a "personal data breach" after emails sent to residents last week were distributed without using the blind carbon copy (BCC) function, allowing recipients to see everyone else on the mailing list. According to local reports, the council sent three emails containing Blue Badge-related updates before issuing a fourth message acknowledging the error and asking recipients to delete the previous emails, including from their deleted items folders. Recipients were also warned to remain alert for suspicious messages following the incident. While the exposed information appears to have been limited to email addresses, the breach is especially sensitive because everyone on the distribution list was receiving communications intended for Blue Badge holders. In practice, that meant recipients could identify hundreds of people as members of a group generally associated with disabilities or mobility impairments. One affected resident told local media that the disclosure had left her upset because most people in her life were unaware she held a Blue Badge. "Honestly, I think it's just disgusting – we've been given the details of hundreds of disabled people, which feels unsafe," she said. In a statement to The Register, a spokesperson at City of York Council said it activated its data breach procedures as soon as the error was identified and is conducting a risk assessment in line with guidance from the UK Information Commissioner's Office. "We're working carefully to establish exactly what's happened, alongside conducting a thorough risk assessment ... to understand any potential impact on individuals," a spokesperson said. “Our investigation is ongoing, and we’ll continue to be as open as possible while ensuring the accuracy of the information we provide.” The spokesperson declined to say how many individuals were affected or whether the issue was caused by human error or a technical issue. The council added that it was assessing whether the incident meets the threshold for notification to the ICO within the statutory 72-hour reporting window. That may depend less on the email addresses themselves than on what the mailing list revealed. A spokesperson at the ICO told The Register: "We can confirm that we have received a data breach report on this matter, and following an assessment of the information provided we have closed the case with advice given.” For all the talk of AI-powered cyber threats, it seems some organizations remain committed to the classics. ®

Pink is the latest goon squad to use fake helpdesk calls to steal creds

4 June 2026 at 22:16
UPDATED A new extortion brand called Pink – which may be a rebrand of BlackFile – uses voice phishing and fake help-desk calls to gain initial access to organizations’ IT environments, steal their sensitive data, and threaten to leak it unless the victims pay a ransom demand. Palo Alto Networks' Unit 42 first spotted the gang, which it tracks as cluster CL-CRI-1147, and its data-leak site, which went live on May 31. “Pink uses vishing and IT impersonation to phish credentials/MFA, then exfiltrates enterprise cloud storage and productivity data to extort victims,” the threat-intelligence biz said in a LinkedIn post. Google Threat Intelligence is not so sure it's a new gang, however. "After retiring the BlackFile brand in May 2026, we assess the group launched the 'Redact' brand and has now potentially surfaced as 'Pink,," Austin Larsen, Principal Threat Analyst at Google Threat Intelligence Group, told us. "This new operation exhibits hallmarks of UNC6671, including similar credential-harvesting infrastructure, data leak site (DLS), and recurring messaging that claims to 'improve the security' of victims who pay. Additionally, we attribute the Pink (CL-CRI-1147) domains recently published by Unit42 to UNC6671." Regardless whether it's brand new or just a new coat of paint, the tactics are very familiar. Pink is one of many goon squads to use these social-engineering tactics to steal employees’ credentials and bypass multi-factor authentication, using this access to burgle companies’ cloud storage and databases. Chaotic crime crew Lapsus$, during its 2021 and 2022 extortion spree that hit Nvidia, Microsoft, and Okta, among others, popularized this style of phone-based intrusions before Scattered Spider picked up the mantle. Scattered Spider is perhaps best known for its 2023 Las Vegas casino digital heists, and reportedly bragged that all it took to break into MGM's networks was a 10-minute call with the help desk. Over the last few years, ShinyHunters has used this same playbook to steal sensitive data from Ticketmaster, AT&T, and other Salesforce customers, and thousands of schools and universities that use Canvas’ digital learning platform. Despite multiple arrests across all three gangs, they keep coming back to victimize more organizations. Most incident responders, including Google’s Mandiant and Unit 42, link many of these criminal collectives to The Com, a loosely knit group of primarily English speakers made up of several interconnected networks of hackers, SIM swappers, and extortionists, with some of its subgroups offering real-life violent crime for hire. According to Unit 42, this latest cluster of extortion activity is also “likely a Com-affiliated actor.” And after investigating “multiple” of these extortion attacks over the past few months, on Monday, they spotted something that led them to Pink’s name-and-shame website. “On June 1, 2026, an existing extortion negotiation that had never received a response, attributed to a likely Com-related cluster, received new communication from a threat actor via a free webmail account,” Unit 42 analysts Richard Emerson and Cuong Dinh said in a Wednesday threat-intel post. “The actor provided a new qTox ID and a leak site associated with the Pink brand, but referenced exfiltrating almost identical information from the original extortion notice.” Pink data thieves set a 72-hour deadline for the victim to respond before leaking the stolen goods. After gaining access to the victim’s account, the criminals snoop around for valuable corporate and customer data from platforms like SharePoint and OneDrive. After exfiltrating the stolen files, Pink attackers use compromised victim accounts and internal Teams messages to extort the company. “The actor reuses second-level domains to target multiple organizations, and the third-level domain typically thematically represents the target,” Emerson and Dinh wrote. They also listed the following phishing domains as indicators of compromise: passkeyadd[.]com passkeydeploy[.]com deploypasskey[.]com Along with these three IP addresses: 185[.]178.208[.]153 (hosted phishing domains) 172[.]93.100[.]252 (accessed compromised accounts) 96[.]232.20[.]66 (residential proxy IP responsible for extortion email creation) Plus, these user-agent strings were observed during data exfiltration: Microsoft.Graph.Client/5.62.0 python-requests/2.28.1 python-requests/2.33.1 Network defenders can use these to assist in threat-hunting efforts. And be very wary of help desk calls, both from people claiming to be employees locked out of corporate accounts and from those purporting to be support staff rolling out a mandatory MFA update or other emergency. ®

OpenAI's agent chained decade-old DoS attacks to crash web servers in seconds

4 June 2026 at 19:08
The next threat your server faces may have been helped along by a bot. OpenAI's Codex agent helped uncover a remote denial-of-service (DoS) exploit that can be launched from a single machine to render vulnerable web servers inaccessible in seconds, according to Calif security researchers. The attack works on default HTTP/2 configurations of major web servers including nginx, Apache HTTP Server, Microsoft IIS, Envoy, and Cloudflare Pingora. As of Thursday, Microsoft IIS and Cloudflare Pingora still don’t have a patch, according to the researchers, although Cloudflare disputes this finding. “Cloudflare's existing architecture and DDoS mitigations automatically detect and protect against this attack, making customers resilient to this vulnerability,” a spokesperson told The Register. “No patch is needed.” “We are aware and actively investigating appropriate mitigations to help keep customers protected," a Microsoft spokesperson told The Register. Calif researcher Quang Luong discovered the exploit, named it HTTP/2 Bomb, and will present the full technical details of the attack at the Real World AI Security conference later this month. In the meantime, there are proof-of-concept exploit scripts on GitHub along with a warning from the AI red teaming security shop: “Please don't point these at infrastructure you don't own.” In a Tuesday blog, Luong says Codex chained two existing DoS attack techniques that have been known for more than a decade - HPACK compression bomb and Slowloris-style hold - and warns that upwards of 880,000 websites supporting HTTP/2 and running one of the vulnerable web servers may be affected. An HPACK bomb attack (also known as CVE-2016-6581) exploits the HTTP/2 header compression algorithm (HPACK) by sending thousands of tiny messages to the server, forcing it to rapidly allocate memory and ultimately crash. Then the Slowloris DoS attack (CVE-2016-8740 and CVE-2016-1546) overwhelms the server by opening legitimate connections and maintaining them as long as possible. Combining the two exhausts the server’s memory and forces it offline. “A home computer on a 100Mbps connection can render a vulnerable server inaccessible within seconds,” Luong wrote. “Against Apache httpd and Envoy, a single client can consume and hold 32GB of server memory in roughly 20 seconds.” The Calif research team disclosed the issue to nginx in April, and the web server’s maintainers fixed it the next day in version 1.29.8, which imports the max_headers directive from freenginx. Apache issued a fix (mod_http2 v2.0.41) the same day that Calif submitted its report, and assigned it CVE-2026-49975. “The fix commits above are public and disclose the vectors directly; any capable AI model can turn those diffs into a working exploit, which is exactly how we found that Microsoft IIS, Envoy, and Pingora are also vulnerable,” the threat hunting team wrote, adding that all three have been notified. In a Wednesday update, Calif pointed to Envoy patches “that appear to mitigate this attack,” and notes that its researchers are still validating the fix to ensure it works. For Microsoft IIS and Cloudflare Pingora, the security sleuths recommend disabling HTTP/2 if possible, or enforcing a cap on the number of HTTP headers a client can send in a single request to the server. The fact that a coding agent - not a human - discovered this attack is notable, according to Calif. “Both halves have been public for a decade,” Luong wrote. “What Codex did was read the codebases, recognize that the two compose, and build the combined attack. That combination is obvious once you see it, and yet as far as we can tell no human had put it together against these servers.” ® Updated at 2023 with statement from Microsoft.

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