Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3aa4f8b63d3e43a…

MALICIOUS

PDF

79.9 KB Created: 2021-03-14 22:22:35 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: cb06ba34ddbbe0d99802d2ac0b9fabc6 SHA-1: 860cbf3e65184d2b29840716b967c72dc33eee85 SHA-256: a3aa4f8b63d3e43ac6ee1b7401d51fd543f66ec100ffd560601d7ab0dc3e097b
186 Risk Score

Malware Insights

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

The file is a PDF containing a large number of external links, many hosted on disposable domains, which is characteristic of a link farm or SEO spam. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically identified as Pdf.Phishing.Trojan. The presence of embedded URLs and the heuristic 'PDF_SEO_LINK_FARM' confirm the attack pattern of directing users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://mezovuduw.ru/123?utm_term=bad+words+in+tamil+song PDF link annotation
    • http://nominasacra.ru/secondary_checkpoint_past_papers_science_frees9dq9.pdfIn PDF document text
    • http://xudogiborijum.66ghz.com/intermediaries_reporting_hmrc.pdfIn PDF document text
    • http://fafasun.iblogger.org/arduino_projects_ideas.pdfIn PDF document text
    • http://shtancircul.site/87937415716dug0k.pdfIn PDF document text
    • http://winoorama.website/keto_diet_recipe_book_freei6zan.pdfIn PDF document text
    • http://reactivaperu-viabcpi.com/912002147583cq5s.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://5053e88e-9e18-4719-890c-32a1cca0295d.filesusr.com/ugd/411503_8c926837a5e54feb813434a8ed21a6a3.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/rejiner/free_homoeopathic_urdu_books.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0ab84126-7524-496f-b860-041136b8c899/metro_2034_gameplay.pdfIn PDF document text
    • https://71e5fc8e-cc9a-4633-96c3-2c70acd464d0.filesusr.com/ugd/f08e01_136f2c42b8c6435fa7504415d5b5e3e8.pdf?index=trueIn PDF document text
    • http://davutawopoban.epizy.com/lodisarovesidironawasiji.pdfIn PDF document text
    • https://s3.amazonaws.com/wemupajese/office_cleaning_checklist_forms_free.pdfIn PDF document text
    • https://b4e79a3f-0083-4b26-8056-4fe87fb46dfd.filesusr.com/ugd/332c1b_d8745dbdf87f43d9a2a33b9f7e02fefa.pdf?index=trueIn PDF document text
    • https://6f8cb219-4830-455d-9ced-b55e65700e85.filesusr.com/ugd/fd30ac_703548f70da940b59e9fd247d6e2434e.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/1466b113-dd1f-46b4-96d9-45f87c4e6d70/have_yourself_a_merry_little_christmas_chord_chart.pdfIn PDF document text
    • https://393102e6-89af-4738-8cad-89662dba8dc5.filesusr.com/ugd/33a16d_2d79bbf8401f4334b8da65420a7858a0.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/bofake/auto_body_shops_near_me_open_sunday.pdfIn PDF document text
    • https://76c9fb28-c10e-4950-85be-37de24a2ede8.filesusr.com/ugd/fa32a6_a814149b1f1f41bca1fdf9779c549ec9.pdf?index=trueIn PDF document text
    • https://459ec6dd-5b69-4322-a182-74abbfaa0e48.filesusr.com/ugd/221eaa_c0d9d1175feb422cbb4b10b52e72e01b.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/789af284-f74a-4e25-a657-ef2d5aa77662/nibolumuvopopasega.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8695bb3c-a596-467d-8f42-244ebea2f703/jetta_transmission_code_location.pdfIn PDF document text
    • https://48cc712b-de5e-493e-a198-f8962849e22b.filesusr.com/ugd/d2751c_0059f50df9724e2cbab81597fe8a657b.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/5a0b62a5-aea3-4e73-bb0e-c71431e6b60a/what_are_common_law_crimes_in_south_africa.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_off0000f860.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF860 5288 bytes
SHA-256: 27af19e56b9ef1efdeff3e128e54024db811c80e725cd974373fbaef14654af0
font_01_sfnt_off00010a59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A59 11644 bytes
SHA-256: 720179d384fe4f651ae5d2a57981935db43c9118ff2c3a026e9c2bfd66dd8d36