Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c1a25f85876072d…

MALICIOUS

PDF

80.8 KB Created: 2021-05-22 01:02:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: c10dafd1ed4e40f6409c6430bc48f069 SHA-1: 8ec36829bcf2bcb73e21a3a074fb198f8b2cea6f SHA-256: 7c1a25f85876072d468211585c9b3482f41c150d892485695bf36cbe1ab7d6bb
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to S3 buckets and Weebly-hosted PDFs, suggesting a link farm or SEO manipulation tactic. One of the primary external links, 'https://jacksth.ru/strik?utm_term=communication+skills+interview+sample+answers', is likely part of this scheme. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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=communication+skills+interview+sample+answers PDF link annotation
    • https://wukaxasupureje.weebly.com/uploads/1/3/4/4/134440875/sixazeluxek.pdfIn PDF document text
    • https://mabavelege.weebly.com/uploads/1/3/0/7/130775551/574465.pdfIn PDF document text
    • https://ropidofizo.weebly.com/uploads/1/3/0/7/130738616/nuvidazovi-lanosefo.pdfIn PDF document text
    • https://tinozewadewuxa.weebly.com/uploads/1/3/1/3/131398338/gezuwub.pdfIn PDF document text
    • https://jelirakiwovul.weebly.com/uploads/1/3/4/8/134867041/guxusemewabemeran.pdfIn PDF document text
    • https://xebutikud.weebly.com/uploads/1/3/0/8/130813588/5340802.pdfIn PDF document text
    • https://gijejutet.weebly.com/uploads/1/3/5/9/135974865/b1c4c1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4406481/normal_6062cadac99af.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4449424/normal_6023d002e4023.pdfIn PDF document text
    • https://xaviloxoganobe.weebly.com/uploads/1/3/1/3/131383750/d7a8114df501b.pdfIn PDF document text
    • https://zanazajerepa.weebly.com/uploads/1/3/4/0/134012527/8847392.pdfIn PDF document text
    • https://borikalubir.weebly.com/uploads/1/3/2/6/132681749/eba7c02.pdfIn PDF document text
    • https://dutesemo.weebly.com/uploads/1/3/1/6/131606066/d61a664ad37e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4402478/normal_6006387b0e80d.pdfIn PDF document text
    • https://pejapuvurexoku.weebly.com/uploads/1/3/1/6/131636728/2115e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4412890/normal_600634826ded6.pdfIn PDF document text
    • https://xibuderopugef.weebly.com/uploads/1/3/4/0/134042602/146339.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4421959/normal_5fee47e3ae08d.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/sirilagewuga/how_to_buy_a_rental_property_with_no_money_down_canada.pdfIn PDF document text
    • https://s3.amazonaws.com/liguwubore/resumen_de_entrevista_de_trabajo_en_ingles_y_espaol.pdfIn PDF document text
    • https://s3.amazonaws.com/filidabut/kulax.pdfIn PDF document text
    • https://s3.amazonaws.com/wunupalezozerud/how_much_does_boards_and_beyond_cost.pdfIn PDF document text
    • https://s3.amazonaws.com/nuxomigo/tomedas.pdfIn PDF document text
    • https://s3.amazonaws.com/zuwimadaneb/tamijawuzis.pdfIn PDF document text
    • https://s3.amazonaws.com/xupimaral/esma_guidelines_suitability_2012.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f276.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF276 5200 bytes
SHA-256: e1be6c0f9de155e9417d9846566381bb247269d7c184519421f1f7311ee4ca83
font_01_sfnt_off0001041f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1041F 10260 bytes
SHA-256: 0ab5d2161ebb3893bf7c3e391e24ce1f1aef284e496baee20dd08bf4ed6365b9
font_02_sfnt_off0001274a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1274A 4324 bytes
SHA-256: 1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361