Malicious PDF — malware analysis report

Static analysis result for SHA-256 906660ca097d962c…

MALICIOUS

PDF

93.1 KB Created: 2021-03-29 08:37:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 71659b2483ca4b5eb4c62f1249dae587 SHA-1: ed409d3debcd64ece9b288a8220cf70289074e68 SHA-256: 906660ca097d962c856b33e4a24b4a21e01624727e4ce48175962d9160066b3b
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous external URLs pointing to other PDF documents hosted on various domains, some of which are identified as disposable. The primary purpose appears to be SEO manipulation or distributing further malicious content through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://leonvi.ru/award?keyword=esercizi+analisi+logica+e+grammaticale+pdf PDF link annotation
    • https://cdn.sqhk.co/zoluxoni/hZlXigg/best_size_tile_for_small_bathroom_shower.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4496607/normal_6059d3eee4ac3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4479684/normal_60343b06c2e4a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4461786/normal_60263572a5c12.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4379973/normal_5fc7d50debec4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4377377/normal_6045eebb5d7da.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4484154/normal_5fec88e61461a.pdfIn PDF document text
    • https://cdn.sqhk.co/noluxokeruma/QIAgfRg/expeditions_tuscaloosa_hours.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383567/normal_604006e62ac40.pdfIn PDF document text
    • https://cdn.sqhk.co/wagomito/ujdOfwL/rome_total_war_barbarian_invasion_units_id.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366369/normal_6038eaf4b91f3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367646/normal_604ed7f8b35e6.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://09235f31-469a-4613-94fc-36d04c1f642a.filesusr.com/ugd/8b6407_b509d42d5caa4802b85e4dd7d88f3e1d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/11f9f209-d5ef-4482-8a41-5817aa01675e/95998577268.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b906dc6d-4a34-49c0-a912-b092e15e6e0f/hamilton_beach_rice_cooker_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/40ddd6e3-1ee1-4be4-b63b-b8439243298c/tuxelojatufuzuriw.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/90772c38-4c69-46f3-b541-f631dbb24fa6/bimovonazimumiva.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8969a5c7-e183-4b3f-a1f3-0fb395ef74c3/20477089272.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/69df8a75-0bd8-4c16-bdc1-ca068825a985/poema_en_lengua_otomi_y_espaol.pdfIn PDF document text
    • https://2ad55d82-15d9-4995-b72c-f03dca93b5f4.filesusr.com/ugd/11b7eb_2893195e969047a892201034cdba4bc5.pdf?index=trueIn PDF document text
    • https://38aad9b5-7a72-45b8-ac81-9fe73ce82000.filesusr.com/ugd/08338c_fb5ffc43cb634c5f997e5129b7a408ec.pdf?index=trueIn PDF document text
    • https://add83a7c-0e31-48b3-928b-061d82ba9144.filesusr.com/ugd/205ae4_60ad837b92e147acb7bfe8aedad8c39c.pdf?index=trueIn 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_off00012dd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DD6 5480 bytes
SHA-256: ce9f89d09dcb0118cb3a9aa3fe997e5d5046b66c33bacd2a2a4447fbb13e0d94
font_01_sfnt_off00014074.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14074 11788 bytes
SHA-256: a454d26c690d7d30f26b8785e6fc0dd92004e76d20c8284fd979306d5ce14b64