Malicious PDF — malware analysis report

Static analysis result for SHA-256 0544a11aefb1e355…

MALICIOUS

PDF

94.2 KB Created: 2021-04-02 07:07:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 6b15403ffda56570acad80dce9286967 SHA-1: a267ab62563358459b4c23a5ac0f1e46bd15156f SHA-256: 0544a11aefb1e355d0eb3c671a3448cfcddbadbd27ab9926a07ac26469a9ad77
186 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to disposable hosting, indicating a link farm for SEO spam or phishing. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of malicious activity, likely aiming to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://kuzutuzo.ru/wix?keyword=photosynthesis+worksheet+answers+biology PDF link annotation
    • https://fujovufizopi.weebly.com/uploads/1/3/2/7/132710671/6651822.pdfIn PDF document text
    • https://cdn.sqhk.co/bowevuva/MDhfRhj/game_on_neon_sign_uk.pdfIn PDF document text
    • https://vinenuji.weebly.com/uploads/1/3/1/4/131453259/kazijavino-tomelosapofaf-mudoxemukag-fonuluf.pdfIn PDF document text
    • http://tryporte.xyz/samsung_55_inch_curved_tv_7_series4hlyw.pdfIn PDF document text
    • http://onlinesos.tech/692255702578017m.pdfIn PDF document text
    • https://dotomogef.weebly.com/uploads/1/3/4/7/134760479/3bb851d.pdfIn PDF document text
    • https://jazujopu.weebly.com/uploads/1/3/0/8/130873842/5e1323f1c4d.pdfIn PDF document text
    • https://cdn.sqhk.co/jabakujivim/FhbLedf/my_factory_cake_tycoon_idle_tycoon_games.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/1647331e-5927-4c9c-8356-8aa78522a451/concise_introduction_to_logic_13th_edition_hurley_solutions_manual.pdfIn PDF document text
    • https://b3a1a1c9-4f8f-4fb8-b7cc-7339030cc889.filesusr.com/ugd/162fe6_a01da8561d444f7490835d0180e8648e.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/80390a38-c6aa-40d7-a962-b996f4d1440e/how_long_is_a_vet_assistant_program.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6e8f955b-a5e9-4d30-b9ae-257614d9f5c0/daily_language_review_grade_5_answer_key_week_21.pdfIn PDF document text
    • https://d1159ab4-cbf5-42eb-897b-83a5e94cd7da.filesusr.com/ugd/536122_e3fe37bdc4a947f9ab6c5eb3ab1ac541.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/4f9d3d2d-cd9b-4b69-8b28-25bad5f38de7/what_is_the_number_1_trending_song.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fda7a713-5736-467b-be52-98f04f1468f3/john_deere_l130_transmission_oil_change.pdfIn PDF document text
    • https://7f1888b6-cdab-4603-9914-1cf81a8b29aa.filesusr.com/ugd/6846fe_aeab4badf8a7456a9a609ee34d5d702e.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/c72836d0-967c-497d-9be2-98309ba03f06/rupuvekinazisubudux.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/50cec094-c9eb-43f0-adb0-47736c78e10e/feneno.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0b302129-e325-459d-be73-2ca058616780/vovinevabikawutexa.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011a6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A6E 5348 bytes
SHA-256: 8fd02ed0950be531a6e65ced5b3a80048a8e873754a28aaca0c4b6dec2935931
font_01_sfnt_off00012caf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CAF 12332 bytes
SHA-256: 7bef330ea33a98e2f47da170c88fbc9b9466f76be78501cfc71c8bc6359c5bd1
font_02_sfnt_off00015634.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15634 16204 bytes
SHA-256: a95eff378c135b1ab40d10b3cd1da1bafbc07f86005f57898d079c90d712ddbd