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Last updated: May 13, 2026 at 5:42 AM UTC
All 208 Vulnerability 72 Breach 41 Threat 88 Defense 7
Tag: shadowserver (4 articles)Clear

Hackers are mass-encrypting websites by exploiting last week's cPanel flaw - 44,000 servers compromised so far in 'Sorry' ransomware attacks

Update on the cPanel flaw covered April 30: attackers are now mass-exploiting CVE-2026-41940 to deploy a Linux ransomware called 'Sorry' that encrypts websites and demands payment to unlock them. Shadowserver confirms at least 44,000 cPanel hosts have been compromised, with hundreds of victim sites already showing up in Google search results. The Sorry encryptor is written in Go, uses ChaCha20 with an embedded RSA-2048 public key (so victims cannot recover files without the attacker's private key), and appends '.sorry' to filenames. KnownHost reports the cPanel flaw was being exploited as a zero-day since at least February 23.

Check
If you run any cPanel or WHM server and have not yet patched, treat the server as already compromised - patch immediately, then start incident response rather than just resuming operations.
Affected
All cPanel and WHM versions before the April 28 emergency patch. ~1.5 million internet-exposed cPanel instances per Shodan, with 44,000 confirmed compromised. Hosting providers, web agencies, e-commerce sites on shared hosting, and any small business website on cPanel are in scope. Anyone whose cPanel was internet-reachable between February 23 and April 28 should assume compromise even if they patched promptly.
Fix
Patch cPanel to a fixed version. After patching, hunt for indicators of compromise (Sorry's '.sorry' file extension, unfamiliar admin sessions, cron entries pointing to /tmp/, modified /var/cpanel/sessions/raw/ files). Restore from clean backups predating February 23 if possible. Block cPanel ports (2082-2087, 2095-2096) at the firewall to non-trusted IPs. Rotate every credential the cPanel host had access to.

Over 10,500 Zimbra servers still vulnerable to actively-exploited XSS as CISA gives federal agencies just three days to patch (CVE-2025-48700)

Shadowserver scan data published Friday shows over 10,500 Zimbra Collaboration Suite instances still unpatched against CVE-2025-48700, a Classic-UI XSS that Synacor fixed in June 2025 but CISA only added to KEV on April 20. Exposed servers split nearly evenly between Asia (3,794) and Europe (3,793). The flaw triggers when a victim simply views a crafted email - no clicks - and runs JavaScript inside their authenticated session for mailbox theft and MFA backup-code retrieval. Zimbra is a recurring APT target: Russia's Winter Vivern, APT29, and APT28 have all run Zimbra-XSS campaigns against NATO and Ukrainian targets.

Check
If you run Zimbra anywhere - including subsidiaries, acquired companies, and overseas regional offices - confirm patch status against CVE-2025-48700 today.
Affected
Zimbra Collaboration Suite 8.8.15, 9.0, 10.0, and 10.1 without the June 2025 security patches. Exploitation requires a user to view a crafted email in the Classic UI; servers using only the Modern UI are not exposed via this specific flaw, but related issues are addressed by the same patch. CVSS 6.1.
Fix
Apply the June 2025 patches across all instances. Where immediate patching is impossible, switch users to the Modern UI as a stopgap and remove webmail from direct internet exposure. Audit the past 60 days of mailbox audit logs for unusual TGZ archive creation, MFA backup-code retrieval, application-password generation, and bulk address-book access. Rotate application passwords issued during the vulnerable window.

Over 1,300 SharePoint servers still exposed to ongoing spoofing attacks a week after Microsoft's patch (CVE-2026-32201)

Shadowserver data shows 1,300+ internet-exposed Microsoft SharePoint servers remain unpatched against CVE-2026-32201, a spoofing flaw Microsoft confirmed as a zero-day and CISA added to its Known Exploited Vulnerabilities catalog the same day the fix dropped in April Patch Tuesday. Fewer than 200 systems have been patched since the update shipped last week. The flaw affects SharePoint Enterprise Server 2016, SharePoint Server 2019, and SharePoint Server Subscription Edition. An unauthenticated attacker can perform network spoofing through improper input validation in a low-complexity attack that needs no user interaction, letting them view sensitive information and modify data, though not affect availability. Microsoft has not described the exploitation technique or attributed the attacks to a specific group, which is unusual for a zero-day and hints at an ongoing investigation. CISA ordered federal agencies to patch by April 28 under Binding Operational Directive 22-01, and given ongoing in-the-wild abuse, private-sector operators should treat that as their own deadline. SharePoint's habit of holding cached Office 365 tokens, SharePoint-signed refresh tokens, and IP on sensitive business processes makes any compromise a serious lateral-movement foothold, not a minor information disclosure.

Check
Inventory every on-premises SharePoint instance in your environment (including dev and staging that may be exposed to the internet) and verify that the April 2026 Patch Tuesday update for CVE-2026-32201 is installed.
Affected
SharePoint Enterprise Server 2016, SharePoint Server 2019, and SharePoint Server Subscription Edition (the 'continuous update' on-premises edition) without the April 2026 security update.
Fix
Install the April 2026 Patch Tuesday security updates for each affected SharePoint version. If a server cannot be patched immediately, pull it off the public internet and put it behind a VPN or Zero Trust gateway, and monitor authentication logs for unexpected token-generation patterns. After patching, audit the last 10 days of SharePoint auth logs and any connected Office 365 federated token issuance for anomalies, since the patch will not retroactively invalidate tokens minted during exploitation.

6,400 exposed Apache ActiveMQ servers still vulnerable to actively exploited CVE-2026-34197 - ShadowServer data shows Asia most impacted

Day-after follow-up to our April 18 coverage: Shadowserver has published telemetry showing 6,400+ Apache ActiveMQ servers exposed online are still vulnerable to CVE-2026-34197, the 13-year-old code injection flaw CISA added to KEV last week with an April 30 federal patch deadline. Geographic breakdown: Asia leads with 2,925 vulnerable servers, North America follows at 1,409, Europe at 1,334. Horizon3's Naveen Sunkavally (who discovered the flaw using the Claude AI assistant as his research tool) is urging admins to treat this as high priority, noting ActiveMQ has been a repeated target for real-world attackers - CVE-2016-3088 and CVE-2023-46604 are both on KEV, with the latter used as a zero-day by the TellYouThePass ransomware gang. The Apache maintainers patched the flaw on March 30 in ActiveMQ Classic 6.2.3 and 5.19.4. Horizon3 recommends searching broker logs for suspicious connections using the internal VM transport protocol with the brokerConfig=xbean:http:// query parameter as an indicator of exploitation.

Check
If you haven't patched ActiveMQ since March 30, check now. ShadowServer data shows thousands of exposed servers are still unpatched two weeks after the advisory.
Affected
Apache ActiveMQ Classic versions 5.x before 5.19.4, and 6.0.0 before 6.2.3, with the Jolokia JMX-HTTP bridge exposed via the web console at /api/jolokia/. ShadowServer identifies 6,400+ internet-exposed vulnerable instances as of April 20.
Fix
Upgrade to ActiveMQ Classic 5.19.4 or 6.2.3. For retroactive detection, search broker logs for connections using the internal VM transport protocol combined with the brokerConfig=xbean:http:// parameter - this pattern indicates an exploitation attempt regardless of success. If an exploit signature is found, treat the broker host as potentially compromised and rotate all credentials that passed through it.