Changed since version 4

• Source references renumbered to match this brief: THN S1, FortiGuard S2, SecurityWeek S3, KEV catalog S4, CISA alert S5; Unit 42 research carried from v4 as S6.
• Contain: added FortiGuard virtual patch FG-VD-59270.0day (FMWP db 25.120) for CVE-2025-61624 attempts as the interim mitigation [S2].
• Verify: added that a virtual-patch IPS hit means an attempt, not success [S2].
• What happened and Verify: added the iked hook that bypasses FortiOS validation for tagged VPN sessions [S1].
• Timeline: added the 2026-10-20 SecurityWeek story; noted its link returned unrelated content [S3].
• Scope enumerate: added checking virtual patch database version per FortiGate [S2].
• Confidence reason and open questions: recorded that S3 adds no corroboration [S3].

What happened

• Initial access came from exploiting FortiJump (CVE-2024-47575) on a telecom MSP's FortiManager [S1][S6].
• The actor exfiltrated running configs, cryptographic material and database files for more than 500 managed FortiGates, then opened unauthorized SSL/VPN sessions to perimeter firewalls [S1][S6].
• The actor exploited CVE-2025-61624 to deploy PEERSTITCH. An auto-script downloaded five components from 23.240.77.233:8085 [S1][S6].
• PEERSTITCH uses ptrace to inject code into /bin/miglogd and /bin/iked. A hooked iked skips default FortiOS security validation for VPN sessions carrying the actor's tag [S1].
• Other tradecraft: an SSH reverse shell via Apache mod_md, impersonating FortiManager to pull configs, stopping syslog, clearing crash logs, and deleting rogue admins and auto-scripts after use [S1][S6].
• CISA added CVE-2025-61624 to KEV on 2026-10-16. It is a path traversal in FortiOS, FortiPAM, FortiProxy and FortiSwitchManager [S4][S5].

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 was created, edited or deleted with ../ in its name. This is how PEERSTITCH was delivered [S1][S6]. Treat it as likely compromise. The actor deletes auto-scripts after execution, 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 url="*/acme/new-acct*" OR url="*/acme/finalize/*") | 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 talked to campaign infrastructure. Outbound traffic to 23.240.77.233 on port 8085 matches the component download [S1][S6]. Port 8084 /acme/ paths match the mod_md reverse-shell channel; inbound SSL-VPN logins match stolen-credential use [S6]. ACME paths alone can be benign if the URL is not on 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 crashlogs, or an admin named FortiGateCloud acted on the device. All are reported actor tradecraft [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 serial or name of the rogue Virtual FortiGate seen by Unit 42 appears, or a .tm archive is referenced [S6]. Treat the FortiManager and every device it manages as in scope. Absence does not clear you; the actor may use other serials.

Verify

• Pull config revisions on each FortiGate. Look for auto-script objects containing ../, unexpected sniffer configs, and admins or VPN groups created then deleted [S1][S6].
• Run 'diagnose debug crashlog read' and look for Signal 11 crashes in miglogd, iked or syslogd [S6].
• With vendor support, check miglogd and iked memory maps for anonymous 16,384-byte rwxp regions and the text patches Unit 42 lists [S6].
• Review VPN/IKE logs for sessions that skipped normal validation; Unit 42 ties tagged sessions to 8550 and 169.254.0.1 markers [S1].
• Scan file and memory images with the Unit 42 YARA rule and compare against its SHA-256 hashes [S6].
• Look for pM.js, a.js, a.wasm, b.js, dd, index.js, index.wasm, ipssem.js and lldprx, and for /tmp/apache2/conf/md-acme.conf [S1][S6].

Scope

Affected

• FortiOS, FortiPAM, FortiProxy and FortiSwitchManager (CVE-2025-61624) [S4][S5]
• FortiManager (CVE-2024-47575), the initial access in this campaign [S1][S6]
• FortiGates managed by a compromised FortiManager, whose configs and keys were exfiltrated [S1][S6]

Only if

• CVE-2025-61624: the attacker is authenticated with an admin profile that has read-write permissions [S5]
• In this campaign, that access came from credentials taken via the compromised FortiManager [S1][S6]

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, any unknown Virtual FortiGates, .tm archives, and which FortiGates it manages.
• All admin accounts, VPN users and groups, including deleted ones visible in config revisions.
• Secrets stored in FortiGate configs: admin and VPN credentials, pre-shared keys, certificates, RADIUS/LDAP binds.
• Management and FGFM (TCP 541) exposure per device, and which hosts each FortiGate accepts management connections from.
• Log retention per device, and gaps in syslog delivery.

Contain

• Before patching or rebooting, export config revisions, event logs and crashlogs. With vendor support, capture memory of miglogd and iked. PEERSTITCH lives in process memory; a reboot destroys those artifacts and cannot be undone [S1][S6].
• Block 23.240.77.233, 47.18.167.159, 45.32.41.202 and 198.199.122.22 at egress and for SSL-VPN [S1][S6].
• Block outbound SSH from firewall management addresses unless required [S1][S6].
• Restrict management and FGFM access to known FortiManager and admin hosts, since the actor impersonated FortiManager [S1][S6]. 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][S6]. Data already taken stays exposed after rotation.
• Apply FG-IR-26-122 [S2] and the FortiManager fix for CVE-2024-47575. Where patching lags, FG-IR-26-122 cites FortiGuard virtual patch FG-VD-59270.0day (FMWP db 25.120) for exploitation attempts [S2]; confirm it is in place.

Eradicate

• Remove rogue auto-scripts, admins, VPN users and groups, and sniffer configs [S1][S6].
• Remove PEERSTITCH components (pM.js, a.js, a.wasm, b.js, dd, index.js, index.wasm, ipssem.js, lldprx) and the rogue md-acme.conf and mod_md job settings, with vendor guidance [S1][S6].
• Clear injected code from miglogd and iked; follow Fortinet guidance on reimaging firmware rather than trusting a running image [S2][S6].
• Patch the root cause: CVE-2024-47575 on FortiManager and CVE-2025-61624 on affected products [S2][S4].

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 crashlogs are retained.
• 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 revises FG-IR-26-122 with fixed versions, new affected products or new mitigations [S2].
• New campaign IPs, hashes or component names are published.
• A hit appears on a FortiGate not managed by a compromised FortiManager, widening scope beyond the MSP pattern.
• CVE-2024-26008 or CVE-2024-26009 is confirmed to play a role in the chain, or lands in KEV [S4].
• Evidence that PEERSTITCH survives reboot or firmware reimage.

Debrief

• Record each device, version, patch date, evidence captured, and hunt results.
• Record which secrets were rotated and when, and any logging gaps found.
• Gap: no fixed versions in the provided material.
• Gap: roles of CVE-2024-26008 and CVE-2024-26009 are not explained; one story calls CVE-2024-26008 an alias of FortiJump, which the sources do not support [S3].
• Gap: whether PEERSTITCH survives a reboot is not stated.
• Gap: mapping of SHA-256 hashes to individual component files is not given.

Detection coverage — checked automatically

Checked automatically 2026-11-01 00:48Z 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:fortimanager"

product:"Fortimanager"

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

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

product:"Fortimanager Cloud"

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

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

product:"Fortiproxy"

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

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

product:"Fortiswitchmanager"

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

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 00:48Z 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

• The SecurityWeek link returned unrelated page content; its claims, including CVE-2024-26008 as a FortiJump alias, are uncorroborated [S3].
• What role, if any, do CVE-2024-26008 and CVE-2024-26009 play?
• Which FortiOS, FortiPAM, FortiProxy and FortiSwitchManager versions fix CVE-2025-61624?
• Does PEERSTITCH persist across reboot or firmware upgrade?
• Are there victims beyond the telecom MSP described?

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.