Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f81f65e6f9873aa…

MALICIOUS

PDF

77.8 KB Created: 2021-05-27 22:35:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 4c3f2b14ba956516ba9ccbaa6b641ffd SHA-1: 53039b4ea849a69a3ee9d1ce300ced0860270cc9 SHA-256: 4f81f65e6f9873aad47477e5dc4b368d32db6cc6d62dc55f252e40a9be2fc62f
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many pointing to disposable hosting services, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. The presence of embedded URLs and the structure of the PDF point towards an attempt to exploit user trust by masquerading as a game manual.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://seumenha.ru/strik?utm_term=keep+talking+and+nobody+explodes+manuale+ita+345 PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4481985/normal_6003b293884be.pdfIn PDF document text
    • https://pibepiramizenat.weebly.com/uploads/1/3/4/7/134735255/dff9e9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4412161/normal_603962b515aa5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4451363/normal_600f07041e5f5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4453336/normal_605239d17f6f5.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4379048/normal_5ff8b518f41e4.pdfIn PDF document text
    • https://rakuwogu.weebly.com/uploads/1/3/4/8/134858672/madumelaseso.pdfIn PDF document text
    • https://sivaxibekexisu.weebly.com/uploads/1/3/4/4/134488572/0864a43.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4403270/normal_5ffe0df7688f8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450513/normal_606085de4f811.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409614/normal_600a7bef4a76f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4500692/normal_604397d564ccb.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4380682/normal_5fff4cfb2a8ec.pdfIn PDF document text
    • https://nibapexi.weebly.com/uploads/1/3/0/9/130969889/bbda9d6dc1.pdfIn PDF document text
    • https://fusopozosasotex.weebly.com/uploads/1/3/4/4/134477759/b7841d051e7ead0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4404122/normal_60541457665ef.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4424991/normal_6052b3283f1fa.pdfIn PDF document text
    • https://rejupalakutasu.weebly.com/uploads/1/3/7/5/137516983/668c0bf5b429.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4501028/normal_602224552edb8.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/b0320747-bfa6-4a55-8739-deec21b29b96/balancing_redox_reactions_in_acidic_solution_practice_problems_with_answers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/072ee77e-d554-4b42-b808-61deced56e9f/how_to_replace_whirlpool_refrigerator_drip_pan.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/96a7cddd-0e81-47af-8ad7-25a12d90a88d/jeligazikotedawe.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_off0000f1b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1B1 5904 bytes
SHA-256: 8918adc2a55f38d1741e9965e4a628b8ee418e99aaeae7470aabf3cd457c595b
font_01_sfnt_off000105d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105D0 10576 bytes
SHA-256: 8abdb534b3a7981aae1c964366f586d99788bbfef7877e8756c469986ccde417