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Threat Actor

DSIRF (Knotweed)

dsirf_knotweed · austrian_commercial_spyware_vendor_psoa · active since 2016-01

DSIRF GmbH (Microsoft codename Knotweed) is an Austrian commercial spyware vendor founded 2016 publicly advertising itself as an information research / forensics / data-driven intelligence services provider but operationally functioning as a private-sector offensive actor (PSOA) developing and selling the Subzero malware toolset to clients while also conducting hack- for-hire operations using its own Knotweed infrastructure per Microsoft MSTIC canonical attribution.

Austrian PSOA hybrid-model attribution via Microsoft MSTIC + MSRC July 28 2022 canonical disclosure ("Microsoft notes that as well as selling the Subzero malware, DSIRF, aka Knotweed, was observed using its own infrastructure in some of the attacks, suggesting more direct involvement in the targeting of victims") with C&C infrastructure + DSIRF-linked GitHub account + DSIRF-issued code signing certificate evidence chain + RiskIQ canonical infrastructure attribution since February 2020 + Citizen Lab / University of Toronto + SOCRadar + TechCrunch + Computer Weekly + ITSecurityGuru + Cyware + Security Boulevard + GridInSoft + Silicon Republic industry coverage.

standalone cluster paralleling variston_heliconia + finfisher_finspy + hacking_team_memento_labs in v0.1.163 commercial spyware / mercenary surveillance vendor operators cell continuation.

operational target profile signature law firms + banks + strategic consultancies with known geographic victims in Austria + Panama + United Kingdom per Microsoft + European + Central American customer base per Microsoft assessment + Microsoft-confirmed unauthorized + malicious targeting (at least one victim confirmed not commissioning red team / penetration testing per Microsoft)

operational attack architecture: (1) cluster-defining Subzero malware toolset hack-for-hire spyware with keylogging + remote shells + screenshots + plugin downloads from C2 server capabilities.

(2) cluster-defining 5-CVE zero-day exploit chain including CVE-2022-22047 Windows CSRSS zero-day (CVSS-rated privilege escalation enabling sandbox escape + system-level code execution, patched July 2022) + CVE-2021- 31199 + CVE-2021-31201 Windows privilege escalation exploit chain combined with CVE-2021-28550 Adobe Reader RCE (all patched June 2021) + CVE-2021- 36948 Windows Update Medic Service privilege escalation 0-day per Microsoft canonical disclosure.

(3) cluster-defining Corelump in- memory primary payload + Jumplump malware loader chain tradecraft with Jumplump downloading and loading Corelump into memory, Corelump loading Subzero payload per Cyware.

(4) signature Excel macro malicious file delivery vector + PDF delivery with Adobe Reader RCE 0-day chain via email attachment with packaged exploit.

(5) cluster-defining DSIRF-issued code signing certificate attribution evidence + DSIRF-linked GitHub account + DSIRF official website + domains forming Microsoft MSTIC evidence chain.

(6) cluster-defining hybrid hack-for-hire + access- as-a-service PSOA model per Microsoft canonical assessment distinguishing DSIRF from pure-vendor PSOAs ("Microsoft used the term PSOA, short for private-sector offensive actor, to describe cyber mercenaries like DSIRF... most PSOAs operate under one or both of two models. The first, access-as-a-service, sells full end-to-end hacking tools to customers for use in their own operations. In the other model, hack-for-hire, the PSOA carries out the targeted operations itself... MSTIC believes that KNOTWEED may blend these models: they sell the Subzero malware to third parties but have also been observed using KNOTWEED- associated infrastructure in some attacks, suggesting more direct involvement")

(7) signature Subzero capabilities device hack including phone + computer + network + IoT device targeting.

(8) signature 2016 founding origin during US presidential election period with Subzero initially advertised as "state trojan analyzing hacking operations" per SOCRadar.

(9) signature alleged Jan Marsalek / Wirecard connection per Security Boulevard reporting context with honest attribution caveat that connection alleged but not corroborated with primary documentary evidence.

cluster fills the Austrian-PSOA + Subzero-malware-toolset + Microsoft- MSTIC-Knotweed-codename + CVE-2022-22047-CSRSS- zero-day + CVE-2021-31199-31201-28550-36948-multi- zero-day-chain + Corelump-Jumplump-loader-tradecraft + hack-for-hire-access-as-a-service-hybrid-model + law-firms-banks-consultancies-targeting + Austria- Panama-UK-known-victims + DSIRF-issued-code- signing-certificate-attribution-evidence position in commercial spyware / mercenary surveillance vendor operators cell.

canonical illustration of Austrian PSOA + hybrid hack-for-hire / access-as- a-service model + multi-zero-day-chain capability + law firms/banks/consultancies-targeting + Corelump/ Jumplump in-memory tradecraft + Microsoft MSTIC C&C-GitHub-certificate evidence chain attribution methodology cited in essentially all subsequent commercial spyware industry analyses through 2016- 2026 period.

austrian_commercial_spyware_vendor_psoa confidence: high 21 aliases
Sigma rules200 YARA rules0 Live IOCs0 CVEs exploited5

Profile

DSIRF GmbH (Microsoft codename Knotweed) is an Austrian commercial spyware vendor founded 2016 publicly advertising itself as an information research / forensics / data-driven intelligence services provider but operationally functioning as a private-sector offensive actor (PSOA) developing and selling the Subzero malware toolset to clients while also conducting hack- for-hire operations using its own Knotweed infrastructure per Microsoft MSTIC canonical attribution. Austrian PSOA hybrid-model attribution via Microsoft MSTIC + MSRC July 28 2022 canonical disclosure with C&C infrastructure + DSIRF-linked GitHub account + DSIRF-issued code signing certificate evidence chain + RiskIQ canonical infrastructure attribution since February 2020. Standalone cluster paralleling variston_heliconia + finfisher_finspy + hacking_team_memento_labs in v0.1.163 commercial spyware / mercenary surveillance vendor operators cell continuation.

Operational target profile
  • Law firms signature.
  • Banks signature.
  • Strategic consultancies signature.
  • Austria + UK + Panama known geographic victims.
  • European + Central American customers.
  • Microsoft-confirmed unauthorized + malicious targeting Operational attack architecture: (1) Subzero malware toolset (cluster-defining): hack-for-hire spyware with keylogging + remote shells + screenshots + plugin downloads (2) 5-CVE zero-day chain (cluster-defining): CVE-2022-22047 CSRSS + CVE-2021-31199 + CVE-2021- 31201 + CVE-2021-28550 Adobe Reader + CVE-2021- 36948 Windows Update Medic Service (3) Corelump + Jumplump in-memory payload chain (cluster-defining): primary in-memory payload + downloader loader tradecraft (4) Excel macro + Adobe Reader RCE PDF delivery vectors (signature) (5) DSIRF-issued code signing certificate (cluster-defining): attribution evidence (6) DSIRF-linked GitHub account (signature): attribution evidence (7) Hybrid hack-for-hire + access-as-a-service PSOA model (cluster-defining): distinguishing from pure-vendor PSOAs The cluster fills the Austrian-PSOA + Subzero- malware-toolset + Microsoft-MSTIC-Knotweed-codename + CVE-2022-22047-CSRSS-zero-day + CVE-2021-31199- 31201-28550-36948-multi-zero-day-chain + Corelump- Jumplump-loader-tradecraft + hack-for-hire-access- as-a-service-hybrid-model + law-firms-banks- consultancies-targeting + Austria-Panama-UK-known- victims position in commercial spyware / mercenary surveillance vendor operators cell.

Aliases

21
dsirf_knotweeddsirfdsirf gmbhknotweedmicrosoft knotweed msticsubzerosubzero malware toolsetcorelumpjumplumpdsirf austrian commercial spyware vendor founded 2016dsirf private sector offensive actor psoa microsoftdsirf cve-2022-22047 windows csrss zero-daydsirf cve-2021-31199 cve-2021-31201 windows privilege escalationdsirf cve-2021-28550 adobe reader rcedsirf cve-2021-36948 windows update medic servicedsirf riskiq attribution infrastructure february 2020dsirf microsoft mstic c2 infrastructure github code signing certificate linkagedsirf jan marsalek wirecard alleged connectiondsirf hack-for-hire access-as-a-service hybrid modeldsirf law firms banks strategic consultancies austria uk panama victimsdsirf july 2022 microsoft disclosure

Notable Campaigns

9
2022DSIRF Knotweed CVE-2022-22047 CSRSS Zero-Day Exploitation (May 2022)
2022DSIRF Microsoft MSTIC July 28 2022 Canonical Disclosure
2022DSIRF Corelump + Jumplump + Subzero Payload Chain Signature
2021-2022DSIRF Law Firms + Banks + Strategic Consultancies, Austria + UK + Panama Victim Signature
2021DSIRF Knotweed Adobe Reader + Windows Privilege Escalation Exploit Chain (2021)
2020DSIRF RiskIQ Infrastructure Attribution Since February 2020
2016-2026Continued Industry Reference Status (2016-2026)
2016-2022DSIRF Hack-for-Hire + Access-as-a-Service Hybrid PSOA Model Signature
2016DSIRF Founded 2016, Austrian Commercial Spyware Vendor Origin

Attribution & Reporting

Attributed by
Microsoft MSTIC (canonical July 2022 KNOTWEED-DSIRF attribution + 5-vulnerability disclosure)Microsoft MSRC (canonical CVE-2022-22047 analysis)RiskIQ (canonical infrastructure attribution since February 2020)Citizen Lab / University of Toronto (canonical Knotweed tracking)SOCRadar (canonical Threats of Commercialized Malware Knotweed analysis)TechCrunch / Lorenzo Franceschi-Bicchierai (canonical July 28, 2022 disclosure coverage)Computer Weekly (canonical Austrian data firm accused of selling malware coverage)The Record / Recorded Future News (canonical DSIRF coverage)ITSecurityGuru (canonical Microsoft Threat Intelligence Center disclosure coverage)Cyware (canonical Corelump + Jumplump + zero-day analysis)Security Boulevard / Richi Jennings (canonical July 2022 Subzero Spyware Secret coverage)GridInSoft / Stephanie Adlam (canonical Austrian Company DSIRF Knotweed Hack Group analysis)Silicon Republic (canonical Spyware group Knotweed targeting firms Europe coverage)Microsoft (canonical PSOA private-sector offensive actor designation)
Key reporting
reportMicrosoft MSTIC (July 28, 2022): canonical KNOTWEED-DSIRF attribution + 5-vulnerability disclosure
reportRiskIQ: canonical infrastructure attribution since February 2020
reportCitizen Lab / University of Toronto: canonical Knotweed tracking
reportSOCRadar: Threats of Commercialized Malware, Knotweed
reportTechCrunch / Lorenzo Franceschi-Bicchierai: canonical July 28, 2022 disclosure
reportComputer Weekly: Austrian data firm accused of selling malware, conducting cyber attacks
reportITSecurityGuru: Microsoft Threat Intelligence Center Links Threat Group to Austrian Spyware Vendor DSRIF
reportCyware: DSIRF Knotweed jointly abused zero-day to deploy Subzero malware
reportSecurity Boulevard / Richi Jennings: Solved, Subzero Spyware Secret Austrian Firm Fingered
reportGridInSoft / Stephanie Adlam: The Austrian Company DSIRF Was Linked to the Knotweed Hack Group
reportSilicon Republic: Spyware group Knotweed targeting firms in Europe (July 2022)

Operational

State sponsor

DSIRF GmbH is an Austrian commercial spyware vendor founded 2016, publicly advertising itself as an information research / forensics / data-driven intelligence services provider but in practice operating as a private-sector offensive actor (PSOA) developing and selling Subzero malware toolset to government + customer clients, and also conducting hack-for-hire operations using its own Knotweed-associated infrastructure per Microsoft MSTIC attribution. Hybrid hack-for-hire + access-as-a-service PSOA model, per Microsoft researchers: "Based on observed attacks and news reports, MSTIC believes that KNOTWEED may blend these models: they sell the Subzero malware to third parties but have also been observed using KNOTWEED-associated infrastructure in some attacks, suggesting more direct involvement." Attribution chain: (1) Microsoft MSTIC + MSRC canonical July 2022 attribution: per TechCrunch + Microsoft researchers: "Microsoft notes that as well as selling the Subzero malware, DSIRF, aka Knotweed, was observed using its own infrastructure in some of the attacks, suggesting more direct involvement in the targeting of victims, which included law firms, banks and strategic consultancies with known victims in Austria, Panama and the United Kingdom." Per Microsoft researchers via The Record / ITSecurityGuru / Computer Weekly: "Now, Microsoft Threat Intelligence Center (MSTIC) analysts are writing about multiple links between DSIRF and the malicious tools used in Knotweed attacks. In particular, we are talking about the C&C infrastructure used by malware.

a DSIRF-linked GitHub account that was used in one of the attacks; a code signing certificate that was issued by DSIRF and used to sign the exploit.

and other posts that linked Subzero directly to DSIRF." (2) RiskIQ canonical infrastructure attribution February 2020: per GridInSoft: "the information security company RiskIQ also discovered that the infrastructure serving malware since February 2020 may be associated with DSIRF, including the official website and domains of the company, which were probably used to debug and prepare Subzero for work." (3) Microsoft PSOA designation canonical: per Computer Weekly + Security Boulevard: "Redmond's Threat Intelligence Centre (MSTIC) described DSIRF as a 'private sector offensive actor' or PSOA... PSOAs such as DSIRF, which it is now tracking as Knotweed in its threat actor matrix, makes its living by selling either full end-to-end hacking tools to the purchaser, similar to how disgraced Israeli spyware firm NSO operates, or by running offensive hacking operations itself." (4) CVE-2022-22047 + CVE-2021-31199 + CVE-2021- 31201 + CVE-2021-28550 + CVE-2021-36948 canonical vulnerability chain: per Microsoft + Computer Weekly + GridInSoft: "Among the 0-day vulnerabilities that Knotweed used in its campaigns, Microsoft highlights the recently fixed issue CVE-2022-22047, which helped attackers to elevate privileges, leave the sandbox and achieve system-level code execution. In addition, last year Knotweed used an exploit chain consisting of two Windows privilege escalation vulnerabilities (CVE-2021- 31199 and CVE-2021-31201) in combination with an exploit for an Adobe Reader vulnerability (CVE-2021-28550). All these bugs were fixed in June 2021. Also in 2021, the group was associated with the exploitation of the fourth 0-day vulnerability that was privilege escalation in the Windows Update Medic Service (CVE-2021-36948)." (5) SOCRadar + Cyware canonical Corelump + Jumplump malware loader analysis: per Cyware: "On infected systems, the attackers deployed Corelump, a primary payload in memory to evade detection, and Jumplump, a malware loader that downloads and loads Corelump into memory. Corelump loads Subzero payload, which has several capabilities including keylogging, running remote shells, capturing screenshots, and downloading plugins from the C2 server." (6) Jan Marsalek / Wirecard alleged connection: per Security Boulevard: "Jan Marsalek" tag in reporting context, DSIRF reportedly linked to former Wirecard COO Jan Marsalek who fled to Russia after Wirecard collapse 2020. Honest attribution caveat: connection alleged in public reporting but not corroborated with primary documentary evidence.

included for completeness. Operational mission objective: Hack-for-hire + access-as-a-service hybrid PSOA model providing Subzero malware toolset to government/customer clients while also operating offensive operations directly via DSIRF-controlled Knotweed infrastructure. Microsoft canonical assessment: "Allowing private sector offensive actors, or PSOAs, to develop and sell surveillance and intrusion capabilities to unscrupulous governments and business interests endangers basic human rights.

" Operational target profile
  • Law firms signature.
  • Banks signature.
  • Strategic consultancies signature.
  • Austria + United Kingdom + Panama known geographic victims per Microsoft.
  • European + Central American customers per Microsoft assessment.
  • Microsoft confirmed unauthorized + malicious targeting, at least one victim confirmed not commissioning red team / penetration testing per Microsoft The cluster fills the Austrian-PSOA + Subzero- malware-toolset + Microsoft-MSTIC-Knotweed-codename + CVE-2022-22047-CSRSS-zero-day + CVE-2021-31199- 31201-28550-36948-multi-zero-day-chain + Corelump- Jumplump-loader-tradecraft + hack-for-hire-access- as-a-service-hybrid-model + law-firms-banks- consultancies-targeting + Austria-Panama-UK-known- victims position in commercial spyware / mercenary surveillance vendor operators cell.
Motivations
austrian_commercial_spyware_vendor_psoa_revenue, hack_for_hire_access_as_a_service_hybrid_model_signature, subzero_malware_toolset_development_and_distribution, multiple_zero_day_exploit_chain_capability_signature, law_firms_banks_strategic_consultancies_targeting_signature
Sectors
Regions

Detection Blind Spots

60 techniques
Across this actor’s 60 mapped techniques, the share covered by each detection layer. Low bars are where you’d be blind if this actor targeted you.
Behavioral / log (Sigma)58/60 · 96%
Analytics (MITRE CAR)30/60 · 50%
Runtime / container (Falco)6/60 · 10%
File / malware (YARA)0/60 · 0%
Network (Suricata/Snort)19/60 · 31%
Vuln scan (Nuclei)0/60 · 0%

Atomic Test Plan

30 techniques
Runnable Atomic Red Team tests covering this actor’s mapped techniques - validate your detections against this specific adversary. Cross-reference the blind spots above. For authorized lab / purple-team use. Open the full builder

Tools Used

0 mapped
Other tooling / TTPs (curation, not ATT&CK-mapped):
SUBZERO CAPABILITIES: KEYLOGGING + REMOTE SHELLS + SCREENSHOTS + PLUGIN DOWNLOADSSUBZERO MALWARE TOOLSET
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