Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f5701a4a84e0b4a…

MALICIOUS

PDF

90.4 KB Created: 2021-05-25 10:28:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 310b27441885194cc3f21eb9afb1e120 SHA-1: 6003a1ecaa4fc526dfe72564ac016cf42117faaf SHA-256: 3f5701a4a84e0b4a0deae890f5a613d7a6ede7bd3451e2cbdd458cf57c7e4226
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded links, with a critical heuristic firing for a malicious redirector. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, appears to contain metadata related to PDF generation and potentially search engine optimization lures, further supporting the link farm attack pattern.

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://yafferge.ru/strik?utm_term=reglas+de+juego+monopoly+pdf In PDF document text
    • https://tisivuvuzudopur.weebly.com/uploads/1/3/0/7/130738638/kasewonipu_tujomomabugetot_wumoxekedaf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4499999/normal_60209327a9d4f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446489/normal_602d531c76677.pdfIn PDF document text
    • https://boxijapemisavar.weebly.com/uploads/1/3/0/8/130874030/furanodurig.pdfIn PDF document text
    • https://siduwibe.weebly.com/uploads/1/3/4/7/134775996/b26753b5604.pdfIn PDF document text
    • https://vuxuminitemup.weebly.com/uploads/1/3/0/8/130874085/689bcd83.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4406169/normal_5fe60b3211b38.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383449/normal_60333db309ec4.pdfIn PDF document text
    • https://bafovulik.weebly.com/uploads/1/3/1/0/131070506/zemusobatikupuki.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4452400/normal_602399440a2a2.pdfIn PDF document text
    • https://mifurujuxix.weebly.com/uploads/1/3/3/9/133997148/7dd34181396bb.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/894cad04-fc34-4294-9f2a-e7740be9c336/36135674733.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/db805c54-2110-42bd-afcd-48d6e2a87dbe/fevojazomuvos.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a28b8e00-4367-4d29-9a95-06315333752b/stephen_king_misery_cast.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e4b08146-4377-4ff5-a478-0be49e503190/7.3_powerstroke_auto_trans_upgrades.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6d1a4d77-544b-4c84-9293-46b2ce3141cd/49668991161.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/06f6ff21-e163-496e-9d46-e1364e5e00ab/54811989143.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8a367c07-d460-49b7-976f-727102b27707/taxivilakulebiximu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e3f335e4-8dc6-440e-bf78-2b8ba2587be9/77806169280.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7c8d0932-948a-4e03-9aed-15984722c21e/19653113639.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0d91a1e7-2c5f-468e-963d-8ebbab0241b2/room_essentials_desk_assembly_instructions.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_off00011e81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E81 5452 bytes
SHA-256: 8abdb44937908210a3ec3c56a42eed3f571ad4ac3cd70a29d214a4c0f9850017
font_01_sfnt_off00013115.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13115 12980 bytes
SHA-256: 839a936c093bef8f089eae966c70014482edd1996db55704c19fadb62218c3de