Malicious PDF — malware analysis report

Static analysis result for SHA-256 0a16923023b5b776…

MALICIOUS

PDF

77.6 KB Created: 2021-03-20 02:52:28 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: b5cc0b804f687d9b3cd5608d3e432b4e SHA-1: d9c792659e073cc836ed781cdfe99e326cd3b6b6 SHA-256: 0a16923023b5b776c932f3e52322b30a27c92e620a50d7a50ce0cbefa3ec36e9
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of external links pointing to other PDF files hosted on various domains, many of which appear to be disposable. This behavior is indicative of a link farm, likely used for SEO manipulation or to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, aligning with a phishing or trojan distribution pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://mezovuduw.ru/award?keyword=acca+f8+notes+pdf+2020 PDF link annotation
    • https://kitabenulo.weebly.com/uploads/1/3/0/9/130969432/c3110df3a0623.pdfIn PDF document text
    • https://cdn.sqhk.co/waxolulum/cncjfjd/29545509991.pdfIn PDF document text
    • https://cdn.sqhk.co/wepigosogo/hfieifH/cool_math_games_papa.pdfIn PDF document text
    • http://good-production20.site/management_books_to_readce7ay.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454556/normal_601e2edaefdf7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388427/normal_6034eb425da34.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4457006/normal_5fc6cc4d7ccf9.pdfIn PDF document text
    • https://jamekefexufi.weebly.com/uploads/1/3/4/8/134866820/filozapeguwew.pdfIn PDF document text
    • http://universal-kirov.ru/radioactive_decay_problems_worksheet_with_answerskbqy5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374983/normal_601d695b30611.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420907/normal_5fd653ec64280.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366377/normal_60410e99ae884.pdfIn PDF document text
    • http://mebelintera.ru/bob_evans_ham_biscuit_benedict_nutrition8n96w.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4418973/normal_5fca69d386518.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4463272/normal_602c6a940c25b.pdfIn PDF document text
    • https://rikulaseno.weebly.com/uploads/1/3/4/4/134471776/6183761.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/2efe4e5f-4c8f-4f84-95b5-a696656962eb/figikiloligedojovabijen.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9fc0180d-d0c1-4578-9847-6c5afbc05d89/pugike.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_off0000f0ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0AB 5476 bytes
SHA-256: aa1150a545b52b2bbb1112e7cce1ea99906c917ed26bd2380f5182e3f8a4a6fc
font_01_sfnt_off0001036c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1036C 11268 bytes
SHA-256: 67578ea7e11c10d9a6bbc73b3b638204e0385346f2d4f9f8839cdfd01c96e68b

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