Malicious PDF — malware analysis report

Static analysis result for SHA-256 6321d61732cb94d1…

MALICIOUS

PDF

77.4 KB Created: 2021-06-06 10:49:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 2945359876251adca7c4dc74f11f437f SHA-1: 219664aea5780dc8e82e4c1177ba8272687dbd67 SHA-256: 6321d61732cb94d1a39e5209c9e2219cc64b2d5bc23894d929f36af173df53c8
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of external links, identified as a link farm. The ML classifier and ClamAV detection strongly indicate maliciousness, with ClamAV specifically flagging it as Pdf.Phishing.Trojan. The primary attack pattern involves directing users to a multitude of external PDF files, likely for SEO manipulation or to distribute further malicious content, rather than direct exploitation within the PDF itself.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://chcial.ru/pbw?utm_term=how+to+check+ac+pressure+with+manifold+gauges PDF link annotation
    • https://jojipizi.weebly.com/uploads/1/3/1/6/131606457/4457872.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4530990/normal_606cd93974469.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4446162/normal_600836b2615b4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476142/normal_602d3e7a5b936.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426073/normal_60500e158b837.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481695/normal_6058fc97003a3.pdfIn PDF document text
    • https://jetebudatupa.weebly.com/uploads/1/3/4/7/134748577/1891761.pdfIn PDF document text
    • https://mezobemubuzopos.weebly.com/uploads/1/3/3/9/133997151/bureturukiduwixixoz.pdfIn PDF document text
    • https://gofetudorupu.weebly.com/uploads/1/3/1/4/131408581/nodevufaruburukegege.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://vatojorisa.pbworks.com/f/bikojesugitadoz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5895e1bf-6831-463a-aafa-01c16d6093b5/lokikitopexel.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a7ca6115-8c59-4c53-961c-9a0fa5c2044e/mirej.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4ec60f53-0974-4b5f-a6de-8b911f3396d9/lekalanugipesirixewonude.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/221fe9ab-89d5-4a74-936e-c6ba3b2303ca/claw_hand_deformity_causes.pdfIn PDF document text
    • http://natutaliva.pbworks.com/w/file/fetch/144664038/how_to_connect_rca_home_theater_sound_bar_to_tv.pdfIn PDF document text
    • http://detomipipu.pbworks.com/w/file/fetch/144529146/que_significa_soar_con_cucarachas_en_el_cuerpo_de_otra_persona.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d39d82db-556b-457e-88fc-44cd0688197d/how_do_you_know_if_your_freezer_stopped_working.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e2ee94ad-a2b0-40db-83c2-9f430eb9b4ba/samsung_rf267aars_icemaker_not_working.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/847e5b2f-27a8-4da7-aeb2-19c62c25f87c/download_aplikasi_whatsapp_plus_anti_blokir.pdfIn PDF document text
    • http://kedetuwi.pbworks.com/f/python_machine_learning_sebastian_raschka_review.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/eb29b5d9-be45-4f86-8b74-d53f96db03fc/rezidumawarexi.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eebc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEBC 5684 bytes
SHA-256: 4243e8b7b96181230cd96c24f0f70a8bd7b6d83ce25bf9612f8de41bec34b6d8
font_01_sfnt_off000101fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101FA 11256 bytes
SHA-256: 007f925cc10fab4cbfe4ea106b6f26676d44e1b2a7abfcd322ef5221b12a0ffa