Malicious PDF — malware analysis report

Static analysis result for SHA-256 a599f8cee2dd0582…

MALICIOUS

PDF

91.3 KB Created: 2021-03-10 13:11:04 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-13
MD5: 6c12555a365d2d467ea9d05d778da02f SHA-1: e4a7236d5465ef3839a0296fedb90ad77f9ebb34 SHA-256: a599f8cee2dd05825d9c9c4e574f8931fdc3c73a1312df5e111b8156c7e67815
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by multiple heuristics and a machine learning classifier, with ClamAV detecting it as a phishing trojan. It functions as a link farm, containing numerous external URLs that point to other PDF documents, likely for SEO manipulation or to distribute further malicious content. The presence of many links on disposable hosting and the overall structure strongly suggest a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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=el+banquero+anarquista+pessoa+pdf PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4417662/normal_5ff2bfbb3c356.pdfIn PDF document text
    • https://cdn.sqhk.co/daxerarugak/y6ibgJt/funny_undertale_animation_memes.pdfIn PDF document text
    • https://babixedijifaz.weebly.com/uploads/1/3/5/3/135385025/1ec682cdbeba3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4444386/normal_60488ca078533.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403531/normal_604491a92d7f0.pdfIn PDF document text
    • https://cdn.sqhk.co/ruwiketi/EAibRja/19610728228.pdfIn PDF document text
    • https://kapavumir.weebly.com/uploads/1/3/5/3/135313873/remimekiradi_wujasedebiri_kunekux_dazozirarixu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://bd7a0a6f-bbfd-49cc-ba41-c3f2778102d9.filesusr.com/ugd/9ea91e_513053add6c34e439ac9135fff482ef9.pdf?index=trueIn PDF document text
    • https://d2d87fd5-5f4d-49aa-ab3c-2263ce4b5d22.filesusr.com/ugd/9169d2_97922b1e273a4fa596b11e3bffd99668.pdf?index=trueIn PDF document text
    • https://5053e88e-9e18-4719-890c-32a1cca0295d.filesusr.com/ugd/411503_cec35105d0954854af0af53a0ea3e816.pdf?index=trueIn PDF document text
    • https://e06e8306-d71e-4c92-aa1b-e8c52eeb44cb.filesusr.com/ugd/bc4951_9ff7f3159336493c9a6bf803ee189c43.pdf?index=trueIn PDF document text
    • https://f98f40d2-b649-4e6b-99af-b89bbf2331ff.filesusr.com/ugd/724bd4_07dd4d0396614c308c46bd00f938a720.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/ede7d2fc-6471-427d-945e-10209e9eb681/how_to_make_plan_for_small_business.pdfIn PDF document text
    • https://4f0754e2-f0c4-47db-826b-83042027646c.filesusr.com/ugd/7a11b0_c50dd58b97414251a1d23d51b7b3d0d4.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/1f94ab32-4633-469a-9caf-24ae298e9f92/maytag_bravos_xl_dryer_review.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7adbff83-b463-4896-9d7e-7e6c03dae9fb/85549385424.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/803e125f-6bf1-4b12-8ef5-41b2f7d12e32/37411444592.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ebc7b3fd-69cf-473c-b5b2-a57d523f98b1/desumironovebixorimuxu.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_off000125f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125F9 5256 bytes
SHA-256: 5685b38f067ceb07d9aac3e9a67c83a69879856984bfaaca991b9017d056814a
font_01_sfnt_off000137dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137DC 11920 bytes
SHA-256: f8cb60d1a93f341a082810b3ac3f4de63881a59ca98e44da127e67b9a6ef0d9c