Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9925e2e1742d8ff…

MALICIOUS

PDF

73.6 KB Created: 2021-04-20 22:18:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: bf73031a57f2e2e064808d7e83bd521b SHA-1: 5b9bd53abd37841071bbcb2095921eccabc917ce SHA-256: a9925e2e1742d8ffca1c5312cee49ede541f3ab9d5afcd0c9f0c25fdef600a2a
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://dafemum.ru/strik?utm_term=bluedio+turbine+t2+plus PDF link annotation
    • https://cdn.sqhk.co/vadetegubufo/hjxhijh/sawefukubadadevofunimafi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4502721/normal_603ce72c8b8c0.pdfIn PDF document text
    • http://verification-help.business/is_milwaukee_school_of_engineering_a_good_schoolfxtq0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4484635/normal_605a190c71296.pdfIn PDF document text
    • https://cdn.sqhk.co/xefilelo/jcCDKhj/51348055361.pdfIn PDF document text
    • http://study-english-04.space/persepolis_satrapi_sparknotesxwzx6.pdfIn PDF document text
    • https://cdn.sqhk.co/gakilofod/1ha5vri/27547771546.pdfIn PDF document text
    • https://cdn.sqhk.co/majumoros/hbij818/boxing_star_game.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4366351/normal_5fc84535be58c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485015/normal_600a4de3693f6.pdfIn PDF document text
    • https://cdn.sqhk.co/sadebupunen/hdgjMgF/basketball_game_length_nba.pdfIn PDF document text
    • https://cdn.sqhk.co/muwazubivotu/hjhuBhg/totabalekenipow.pdfIn PDF document text
    • http://begdas.space/anatomy_and_physiology_1_lab_exam_2vyoie.pdfIn PDF document text
    • https://cdn.sqhk.co/laruxibut/BDVhgnG/final_castle_defence_idle_rpg.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://s3.amazonaws.com/zerejibixupav/yookoso_workbook_answers.pdfIn PDF document text
    • https://s3.amazonaws.com/xeponodij/what_are_some_practices_of_christianity.pdfIn PDF document text
    • https://s3.amazonaws.com/zowibatev/godejawasi.pdfIn PDF document text
    • https://s3.amazonaws.com/xakusineba/13833723478.pdfIn PDF document text
    • https://5a3bb923-6189-432a-a936-48d98632e4cf.filesusr.com/ugd/a86d68_3854da0691564708b9c6bf896037bdd5.pdf?index=trueIn PDF document text
    • https://5e1449e8-5ae4-4a15-bc7a-ee23795bc964.filesusr.com/ugd/3a34a5_c8bd0a75a096468fb259915ed9349ed2.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ca0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA0B 2952 bytes
SHA-256: e211f2d6e0d1bf1fd17bd5150bc2724fb7c0f1d37b1c69b855d9dcad8de34ab0
font_01_sfnt_off0000d499.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD499 4948 bytes
SHA-256: c5d5c1e764cfb70ac0b00793192d26f013043c3ea10b82afc606a4a96df838cf
font_02_sfnt_off0000e569.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE569 10492 bytes
SHA-256: b183aa649fa13345c54b2bee2e2740bddcfe27bbb18611ae2aaf0451415ae289
font_03_sfnt_off0001096d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1096D 4324 bytes
SHA-256: 9f355172d696dda274cac500966718f112ce76951f19577ac4888987ea6471b2