Malicious PDF — malware analysis report

Static analysis result for SHA-256 ead4bacd1afff3e0…

MALICIOUS

PDF

78.2 KB Created: 2021-03-16 17:47:18 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: a1782be75d3c6341fe3eede31874234c SHA-1: b529222f98830742e98d9cecbda528c30a7c8dc6 SHA-256: ead4bacd1afff3e01b57cf0921984af989cd1ec705696b159e8c2c2de728d394
126 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, suggesting a link farm or SEO manipulation tactic. 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 websites, possibly as part of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://jacksth.ru/strik?utm_term=fundamentals+of+english+grammar+5th+edition+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4471481/normal_5fe8906295001.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4474752/normal_6049177a2f368.pdfIn PDF document text
    • http://vitebim.22web.org/gone_with_the_wind_book_criticism.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408862/normal_600fbc5d8ed65.pdfIn PDF document text
    • http://bukivagixunok.22web.org/louisiana_earned_income_credit_worksheet.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446272/normal_602d05152a0dd.pdfIn PDF document text
    • http://radoruraruj.22web.org/sendai_mediatheque_structure.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4500183/normal_6034294e7ea67.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/farefasejikap/mebolutotiril.pdfIn PDF document text
    • http://mofomunor.rf.gd/market_leader_business_english_course_book.pdfIn PDF document text
    • https://s3.amazonaws.com/libusamagowuvo/worefewosewatilimuxet.pdfIn PDF document text
    • https://s3.amazonaws.com/tofizo/bangalore_days_songs_video.pdfIn PDF document text
    • http://vaduxovogemuke.epizy.com/synthetic_division_no_remainder_worksheet.pdfIn PDF document text
    • https://141ebdc9-a3c9-4c6d-b8f9-366dbf139dec.filesusr.com/ugd/46bfb0_329ac56b538c4381a87240446d6e00f7.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/7172e566-26cb-47d5-9f33-f01122def765/what_is_fervent_in_the_bible.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2a768d3c-279e-4b38-9162-0eb7c9d2eab3/funny_grade_5_speech_topics.pdfIn PDF document text
    • https://s3.amazonaws.com/sixolose/46371608284.pdfIn PDF document text
    • https://s3.amazonaws.com/vekodupiwarobi/alveus_formic_20.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f5335f8d-b0d4-40f5-9e53-ed253008547a/drawing_right_side_brain.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/23abad45-f3bc-4b16-989c-90ec9c80321e/guess_the_movie_name_by_picture_with_answers_tamil.pdfIn PDF document text
    • https://4d75d3c9-3a4d-4df6-84ab-e48b83d723e5.filesusr.com/ugd/cdb50c_ec021bcaa01848bbbb94b2cc73f1ad4f.pdf?index=trueIn PDF document text
    • https://3bcdeb60-9876-4d14-bc0a-1dd1632c647c.filesusr.com/ugd/16a96a_530b93f362c747dab5337c0766c1097e.pdf?index=trueIn 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_off0000e69e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE69E 5532 bytes
SHA-256: 4f2960131d05e5d7bae3e93c833ff76de1ba1d5b47bcf7a861c19ece3224d0d6
font_01_sfnt_off0000f94e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF94E 20392 bytes
SHA-256: 69244c08719c2f9dfe971511f6b916a61192234a5cf29e78016e96a061dbec42