Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b1e3f480f52ee4e…

MALICIOUS

PDF

91.8 KB Created: 2021-05-02 06:35:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: 517bcd03d3e3607cc2d53c668e827109 SHA-1: f21f8932b36d921762bc980252ec8c4c76a958fe SHA-256: 8b1e3f480f52ee4eba4987cf34efcce26efe88bdb063f308c0c5ee72cded768f
126 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristic analysis revealed it functions as a link farm, embedding a large number of external URIs, with a primary suspicious URL being https://vilenefex.ru/strik. This suggests the document is designed to redirect users to potentially harmful websites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 5

  • 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 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://vilenefex.ru/strik?utm_term=how+to+find+the+z+value+from+table PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4454672/normal_602da178385ba.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4484126/normal_603a4bc243444.pdfIn PDF document text
    • https://cdn.sqhk.co/wenisuvuroju/JMtwche/cuba_covid_travel_advice.pdfIn PDF document text
    • https://kepupumi.weebly.com/uploads/1/3/4/6/134616340/fapar-lajudoda.pdfIn PDF document text
    • http://tublitalia.space/alesis_dm6_kick_drum_not_workingy8aot.pdfIn PDF document text
    • https://cdn.sqhk.co/defisepeniba/hfUrNjd/bowl_over_idiom_synonym.pdfIn PDF document text
    • https://bifutizuwosedi.weebly.com/uploads/1/3/4/6/134645412/loxuvirade.pdfIn PDF document text
    • http://kurs1.xyz/sewiziguwojupadoperurcoke.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409610/normal_5fdc11bc647b6.pdfIn PDF document text
    • https://zedodunojoponex.weebly.com/uploads/1/3/6/0/136083391/seselozomus_kulofepedelor_segubutef.pdfIn PDF document text
    • https://cdn.sqhk.co/wigalefu/ghhfgf1/unicorn_color_by_number_pixel_art_coloring_online.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4467003/normal_5fe0f5bc12591.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481064/normal_5fd7974591963.pdfIn PDF document text
    • http://sexedate69.site/bbc_cricket_theme_tune_freepjlew.pdfIn PDF document text
    • https://wosobariwosamu.weebly.com/uploads/1/3/4/3/134372044/04b0e89.pdfIn PDF document text
    • https://jivowewowigopap.weebly.com/uploads/1/3/1/6/131606746/rupedejifiteje-zebajiboliravev-nizel-bavofimafavu.pdfIn PDF document text
    • https://zisifogadudup.weebly.com/uploads/1/3/4/7/134765868/givofebakiji-zewulu-fijasulu-jumimax.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/960c9ed9-ed5a-4ca4-accf-a2b640f004d7/how_can_i_renew_my_license_during_covid.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/98fcbe31-2035-4225-9f0d-aae27f031734/8955276700.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3cadba07-c89a-432c-9fb3-f22ba5a2f23d/ford_ranger_wildtrak_2018_service_intervals.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5aacf835-dbcd-45cf-9ba4-92fd913fb3d6/ley_reforma_laboral_puerto_rico_2017.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7a05b247-d54f-4683-8233-7f4c2c2239c1/ramefadipozevosupax.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_off0001103a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1103A 5272 bytes
SHA-256: 5007f9199418326f320d89bf46d00f40f42039cb46b2a31d00203490360934ff
font_01_sfnt_off0001221c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1221C 11684 bytes
SHA-256: e48e0f059fb5d348b0507250f89017ff272204d36e92ea3b73fe80b994d137fb
font_02_sfnt_off00014a5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14A5E 16232 bytes
SHA-256: e73877ea53ff0d565256fafdf5b8734db755f1321e02d34d1c78ba92c4ef1476