Changed since version 18

• Sources renumbered to this run's list: The Hacker News is now S1, FortiGuard S2, SecurityWeek S3, CISA KEV catalog S4 and CISA alert S5. Unit 42 is retained as S6 from v18, though it is not in today's source set.
• Re-sourced claims that The Hacker News now confirms: the auto-script download from 23.240.77.233:8085, the ptrace injection into miglogd and iked, the mod_md reverse shell, FortiManager impersonation, log tampering, and deletion of rogue admins and auto-scripts [S1].
• Verify: added a check for the reported 8550 and 169.254.0.1 markers in VPN traffic of tagged sessions (the new vendor-stated behavior) [S1].
• Verify: added index.js to the leftover component list, and added benign look-alikes [S1].
• Added eradicate and re-entry triggers grounded in [S1][S2], and a timeline including the KEV due date of 2026-10-19 [S4].
• Open questions: added the SecurityWeek read failure and its conflicting FortiManager placement of CVE-2025-61624, the unsupported firmware-push hunt, and inconsistent story dates [S3].

What happened

• CL-STA-0954 (UNC5820) got into a telecom MSP's FortiManager through FortiJump (CVE-2024-47575). It took running configs, cryptographic material and database files covering 500+ managed FortiGates [S1][S6].
• The actor used that data to open unauthorized SSL-VPN sessions to perimeter firewalls. It then exploited the FortiOS CLI path traversal CVE-2025-61624 to deploy PEERSTITCH [S1].
• An auto-script downloads five components from 23.240.77.233:8085. PEERSTITCH ptrace-injects code into /bin/miglogd and /bin/iked. VPN sessions carrying a tag skip FortiOS validation [S1].
• The actor stopped syslog, cleared crash logs, and deleted rogue admins and auto-scripts after use. It spawned SSH reverse shells through Apache mod_md and impersonated FortiManager to pull configs from other firewalls [S1].
• CISA added CVE-2025-61624 to KEV on 2026-10-16 based on evidence of active exploitation [S5]. Fortinet's fix is FG-IR-26-122, with virtual patch FG-VD-59270.0day in FMWP db 25.120 [S2].

Timeline

Detect

FortiGate auto-script objects with path traversal names · FortiOS system event / config change logs (syslog or FortiAnalyzer forward)

index=* devid=* type="event" subtype="system" (cfgpath="system.auto-script" OR msg="*auto-script*") (cfgobj="*../*" OR msg="*../*") | stats count min(_time) as first_seen max(_time) as last_seen values(action) as action values(cfgobj) as cfgobj values(msg) as msg by devname user ui

A hit means: An auto-script object with ../ in its name was created, edited or deleted. Unit 42 names ../../../../setup and ../../tmp/apache2/conf/md-acme.conf [S6]. Treat a hit as likely compromise. The actor deletes auto-scripts after use, so a delete event alone matters [S1].

Traffic, web or SSL-VPN sessions involving campaign infrastructure · FortiGate traffic, web filter and VPN event logs; proxy/egress logs

index=* (srcip IN ("23.240.77.233","47.18.167.159","45.32.41.202","198.199.122.22") OR dstip IN ("23.240.77.233","47.18.167.159","45.32.41.202","198.199.122.22") OR remip IN ("23.240.77.233","47.18.167.159","45.32.41.202","198.199.122.22") OR url="*/pM.js" OR (dstport=8085 (url="*/a.js" OR url="*/a.wasm" OR url="*/b.js" OR url="*/dd")) OR (dstport=8084 (url="*/acme/*" OR url="*/directory")) OR url="*/acme/new-acct*" OR url="*/acme/finalize/*" OR url="*/acme/order/*" OR url="*/acme/authz/*") | stats count min(_time) as first_seen max(_time) as last_seen values(dstport) as dstport values(url) as url values(action) as action values(user) as user by devname srcip dstip

A hit means: A device contacted campaign infrastructure. A pM.js, a.js, a.wasm, b.js or dd fetch from 23.240.77.233:8085 matches the component download [S1]. Port 8084 /directory and /acme/ paths match the mod_md SSH reverse-shell channel [S6]. Inbound SSL-VPN logins from these IPs match stolen-credential use [S1][S6]. ACME paths alone can be benign if the peer is not a campaign IP.

Logging daemons killed, crashlogs cleared, or FortiGateCloud admin activity · FortiOS CLI audit and system event logs

index=* devid=* (msg="*killall*miglogd*" OR msg="*killall*syslogd*" OR msg="*crashlog clear*" OR user="FortiGateCloud") | stats count min(_time) as first_seen max(_time) as last_seen values(msg) as msg values(ui) as ui by devname user

A hit means: Someone stopped logging or cleared crash logs, matching the actor's log tampering [S1][S6]. An admin named FortiGateCloud pulling running configs over FGFM matches the actor's FortiManager impersonation [S1][S6]. Also check each device's syslog stream for gaps. A successful kill produces silence, not events.

Rogue Virtual FortiGate registration on FortiManager · FortiManager event / device management logs

index=* ("FMG-VMTM23017412" OR ("Virtual FortiGate" AND "localhost") OR ".tm") devid=* | stats count min(_time) as first_seen max(_time) as last_seen values(msg) as msg by devname

A hit means: The rogue Virtual FortiGate serial or name appears, or a .tm archive is referenced [S6]. Treat the FortiManager and every device it manages as in scope. Absence does not clear you, since the actor may use other serials. The bare .tm term is noisy, so confirm by context.

Verify

• Pull config revisions on each FortiGate. Look for auto-script objects containing ../ and for admins or VPN groups that were created then deleted [S1][S6].
• Run diagnose debug crashlog read. Signal 11 crashes in miglogd, iked or syslogd are a reported indicator [S6].
• pM.js deletes itself, so its absence does not clear a device [S1]. Check /data2/template/ for leftover components such as lldprx, ipssem.js, index.js and index.wasm [S1][S6].
• Scan recovered files and memory images with Unit 42's YARA rule u42_apt_linux_PEERSTITCH_fortigate_implant. Its strings include /bin/miglogd, /bin/iked, 169.254.0.1, /tmp/apache2/conf/md-acme.conf and /proc/%d/mem [S6].
• Review SSL-VPN sessions that authenticated without the expected validation steps. The hooked iked lets tagged sessions bypass validation [S1]. Look for traffic carrying the reported 8550 and 169.254.0.1 markers [S1].
• Check the Apache mod_md job.json for MDChallengeDns01 mapped to /bin/node, or entries like kali@23.240.77.233:8084 with -F /tmp/upfile/ssh_config [S6].

Scope

Affected

• FortiOS, FortiPAM, FortiProxy and FortiSwitchManager (CVE-2025-61624) [S2][S5]
• FortiManager (CVE-2024-47575), the initial access in this campaign [S1]
• FortiGates managed by a compromised FortiManager, whose configs and keys were exfiltrated [S1]

Only if

• CVE-2025-61624 requires an authenticated attacker with an admin profile that has read-write permissions [S5].
• In this campaign, that access followed credentials and keys taken via the compromised FortiManager [S1].

Not affected if

None stated by the sources.

Fixed in: See Fortinet FG-IR-26-122 [S2]. Fixed versions are not stated in the provided material.

Enumerate

• Every FortiOS, FortiPAM, FortiProxy, FortiSwitchManager and FortiManager instance, with its running version.
• For each FortiManager: all registered devices, unknown Virtual FortiGates, .tm archives, and the FortiGates it manages [S6].
• All admin accounts, VPN users and groups, including deleted ones visible in config revisions [S1][S6].
• Sniffer configs on FortiGates, especially those capturing TCP 3696-3706, UDP 69, 1812/1813 or TCP 389 [S6].
• Secrets stored in FortiGate configs: admin and VPN credentials, pre-shared keys, certificates, RADIUS/LDAP binds [S1].
• Management and FGFM (TCP 541) exposure per device, and the hosts each FortiGate accepts management connections from, since the actor impersonated FortiManager to pull configs [S1].

Contain

• Before patching or rebooting, export config revisions, event logs and crash logs. With vendor support, capture memory of miglogd and iked, where PEERSTITCH runs [S1]. A reboot destroys in-memory artifacts and cannot be undone.
• Block 23.240.77.233 at egress and for SSL-VPN [S1]. Also block 47.18.167.159, 45.32.41.202 and 198.199.122.22 [S6].
• Block outbound SSH from firewall management addresses unless it is required. The actor used mod_md to spawn SSH reverse shells [S1].
• Restrict management and FGFM access to known FortiManager and admin hosts. Remove internet exposure of FortiManager and admin interfaces.
• Disable unknown admins and VPN accounts. Remove unauthorized sniffer configs and rogue FortiManager device registrations [S6].
• If a FortiManager may be compromised, rotate every credential and key stored in FortiGate configs [S1]. Rotation does not undo exposure of data already taken.
• Apply FG-IR-26-122 and the FortiManager fix for CVE-2024-47575. Where patching lags, confirm FortiGuard virtual patch FG-VD-59270.0day (FMWP db 25.120) is in place [S2].

Eradicate

• Remove rogue auto-scripts, admin accounts and VPN groups, and remove the components in /data2/template/ (pM.js, a.js, a.wasm, b.js, dd and their renamed forms) [S1][S6].
• Remove PEERSTITCH code injected into miglogd and iked, with vendor guidance; the sources do not describe a removal procedure [S1].
• Remove mod_md job entries that launch SSH reverse shells [S1][S6].
• Close the root causes: CVE-2024-47575 on FortiManager and CVE-2025-61624 on FortiOS and related products [S1][S2].

Recover

• Before restoring, confirm patched firmware, a config matching a known-good baseline, and rotated secrets [S2].
• Confirm syslog flows continuously from each device and crash logs are retained [S1].
• Confirm no 16KB rwxp regions remain in miglogd and iked, and the YARA rule finds nothing [S6].
• Afterwards, keep the four hunts running. Alert on new auto-scripts, short-lived admins, sniffer config changes, outbound SSH from firewalls, unexpected FGFM peers and logging gaps [S1][S6].

Re-enter the loop when

• Fortinet updates FG-IR-26-122 with fixed versions, new affected products or new indicators [S2].
• Unit 42 or another vendor publishes new IPs, files or serials for CL-STA-0954.
• A primary source clarifies the roles of CVE-2024-26008 or CVE-2024-26009 in the chain.
• A hunt hits on any device, or a FortiManager is found compromised: widen scope to every device it manages [S1].
• A source reports that PEERSTITCH persists across reboot or firmware upgrade.

Debrief

• Record each device, version, patch date, evidence captured and hunt results.
• Record which secrets were rotated and when, and any logging gaps found.
• Record VPN sessions that could not be validated, given the iked bypass [S1].
• Gap: the provided material does not state fixed versions.
• Gap: the sources do not explain the roles of CVE-2024-26008 and CVE-2024-26009. One summary calls CVE-2024-26008 a FortiJump alias, but the pipeline could not read that source [S3].
• Gap: the sources do not say whether PEERSTITCH survives a reboot.

Detection coverage — checked automatically

Checked automatically 2026-11-01 09:09Z from public sources: 18 published, 27 nothing found, 0 not machine-checkable, 0 failed. "Nothing found" means the public source answered and had nothing, as of that moment; a feed covers only its newest posts. Re-checked daily.

Exposure queries — generated automatically

vuln:CVE-2024-47575

vuln:CVE-2024-26008

vuln:CVE-2025-61624

cpe:"cpe:/a:fortinet:fortiproxy"

product:"Fortiproxy"

host.services: (software.product = "Fortiproxy")

cpe:"cpe:/a:fortinet:fortiswitchmanager"

product:"Fortiswitchmanager"

host.services: (software.product = "Fortiswitchmanager")

cpe:"cpe:/a:fortinet:fortimanager"

product:"Fortimanager"

host.services: (software.product = "Fortimanager")

cpe:"cpe:/a:fortinet:fortimanager_cloud"

product:"Fortimanager Cloud"

host.services: (software.product = "Fortimanager Cloud")

http.title:"FortiManager"

http.title:"FortiProxy"

Internet-wide count, trend

Shodan's count of matching services on the whole internet, one point a day; the scope (your ranges) is never part of it. A count moves with Shodan's crawl as much as with patching, so read the direction, not the digit.

NVD names 2 more affected products (libraries and embedders); the CVE query covers them where Shodan has fingerprinted the version.

Banner spellings: a model read 4 from the NVD names and this card's text (former and marketing names, console titles); 2 matched something on Shodan and are shown above, the rest were dropped.

Scope every query in your own tool, never in a shared document: Shodan `net:<your_ranges>`, `org:"<your_org>"` or `hostname:<your_domain>` (or a Shodan Monitor network alert, which applies the scope for you); Censys `host.ip: <your_ranges>` or `host.dns.names: <your_domain>`. Then compare the banner version with the affected range. Generated automatically 2026-11-01 09:09Z from the CVE ids and NVD's CPE configurations, each Shodan query counted against Shodan itself; re-built daily with the coverage check.

Open questions

• Unit 42's report is not in this run's source set. Details marked [S6] (extra IPs, YARA rule, FMG serial, sniffer ports, mod_md job.json, crash signals) are carried from prior draft v18 and need analyst confirmation against the Unit 42 page.
• The 2026-10-20 story says the SecurityWeek link returned unrelated content [S3], and it places CVE-2025-61624 on FortiManager. CISA and The Hacker News place it on FortiOS and related products [S1][S5]. That claim is not adopted.
• The 2026-10-20 story suggests hunting for firmware pushes from FortiManager. No readable source describes firmware pushes, so no hunt was added.
• The thread is labelled oldest first, but stories are dated 2026-10-20, 2026-10-19 and 2026-10-16, and the brief date is 2026-10-16. Confirm the story dates.
• The meaning of the 8550 marker in tagged VPN traffic is not explained in the provided material [S1].
• Fixed versions for FG-IR-26-122 are not stated in the provided material [S2].

Sources

• [S1] https://thehackernews.com/2026/10/attackers-exploit-fortios-flaw-to.html · The Hacker News
• [S2] https://fortiguard.fortinet.com/psirt/FG-IR-26-122 · FortiGuard Labs
• [S3] https://www.securityweek.com/exploited-fortinet-bug-linked-to-stealthy-fortigate-implant-in-telecom-hack/ · SecurityWeek
• [S4] https://www.cisa.gov/known-exploited-vulnerabilities-catalog · CISA
• [S5] https://www.cisa.gov/news-events/alerts/2026/10/16/cisa-adds-two-known-exploited-vulnerabilities-catalog · CISA

Public OSINT only. AI-generated by the pipeline; structure follows the DAIR model from Dynamic Incident Response (Joshua Wright). Published automatically once it crosses the publish bar.