Malicious PDF — malware analysis report

Static analysis result for SHA-256 57e03644c977247b…

MALICIOUS

PDF

83.3 KB Created: 2021-06-07 10:49:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 7e84511c1acefe70e90f947f08bc7399 SHA-1: 0a3549fa3edb7d61dcac5a8c37331201058a99f7 SHA-256: 57e03644c977247b33d915202cb9bacad275f958ff3060465418fd850387061c
126 Risk Score

Malware Insights

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

The PDF contains a significant number of external links, identified as a link farm, with many pointing to disposable hosting services. The ML classifier strongly indicates maliciousness. While no scripts were directly extracted, the PDF structure and embedded URIs suggest an attempt to redirect users to potentially malicious or SEO-manipulated content, possibly as a precursor to further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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://seumenha.ru/123?utm_term=chico+buarque+apesar+de+voc%25C3%25AA PDF link annotation
    • https://jemusutagutuf.weebly.com/uploads/1/3/5/3/135390091/b327704a.pdfIn PDF document text
    • https://vuduleputasi.weebly.com/uploads/1/3/4/4/134488699/fizolefuv-lusavalorulen-wujuror-dutisotoxij.pdfIn PDF document text
    • https://ramageputa.weebly.com/uploads/1/3/1/6/131637054/218286.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4494451/normal_5fe02a7e63532.pdfIn PDF document text
    • https://zilifanaj.weebly.com/uploads/1/3/4/4/134444715/ruvusisewif-repilogumutomes-zivigupapa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450514/normal_6029f1ce12a14.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4428062/normal_5fe81e2276409.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/7df79904-ba3c-47cb-9c8a-5650faac7074/microsoft_project_manager_interview_questions.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fcc78d57-ed67-4a51-ac1c-dab911f116d9/amsco_ap_human_geography.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f0a61922-3e3d-41d7-ab17-6a5b982fb4e8/jusigono.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/14e2860f-8930-4bbd-9e38-60f6dce8d8ae/5th_grade_explanation_writing_topics.pdfIn PDF document text
    • http://natutaliva.pbworks.com/w/file/fetch/144664008/6751373273.pdfIn PDF document text
    • http://mefijunov.pbworks.com/f/53181496414.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e0d20096-9baf-401f-a9fc-97f713b0be60/jipibogojazamoziveb.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e8c6f83c-bf5f-4dc6-9076-7839e0f8c9c8/les_mis_music_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/59505464-b8dc-4d28-bcee-b7d067c23f74/amana_microwave_rcs10ts_parts.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c8cf4ba6-4774-4169-ac80-36a11397c905/black_and_decker_battery_trimmer_edger.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/db5ee074-0608-4e01-b8ac-8261df998f09/douglas_county_co_public_records_search.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3dc6e15a-b213-467d-a6a8-7c067a102909/65488640492.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_off0001036e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1036E 5512 bytes
SHA-256: b219180afc9b863416c10169c980961ae138fa72cdcdbe0e9d7b13b47752a582
font_01_sfnt_off000115db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115DB 13272 bytes
SHA-256: a49263c0d40957d21267d0a2ddc5cbf0eed60249c08f492968994c009834b82f