Malicious PDF — malware analysis report

Static analysis result for SHA-256 0bc988da362e953c…

MALICIOUS

PDF

83.5 KB Created: 2021-03-09 19:11:21 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: 0ad94f4c3760784aafc02f73d1b324e9 SHA-1: 9dee4627c02ef011617472127662c93db3306035 SHA-256: 0bc988da362e953cec2669a423c3b63d58fdae6d56c182a594a43eb2b8126e28
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of external links pointing to various PDF files hosted on disposable domains, as indicated by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO spam. The document body is heavily obfuscated and contains metadata from wkhtmltopdf, suggesting it was programmatically generated.

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://leonvi.ru/award?keyword=african+culture+book+pdf PDF link annotation
    • http://fomijegi.mypressonline.com/post_office_ssa_account_balance_check.pdfIn PDF document text
    • https://gijufonuvaxi.weebly.com/uploads/1/3/4/8/134874477/kujinumu-rumonudamod.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4480899/normal_5feb4a6848df9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4474450/normal_602754eaf3513.pdfIn PDF document text
    • http://pidijajuwupurop.medianewsonline.com/jimimuduvivu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4406481/normal_602661ff45a48.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370266/normal_601a38ce2626f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4427094/normal_5ff21d6692eb2.pdfIn PDF document text
    • http://tapozifokun.mywebcommunity.org/zifabafagi.pdfIn PDF document text
    • https://cdn.sqhk.co/daviluzabidi/DhhKiiM/witope.pdfIn PDF document text
    • https://wijugola.weebly.com/uploads/1/3/2/3/132303023/xujupefijerusa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380890/normal_60359d4d78648.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379839/normal_602a3df95ca7b.pdfIn PDF document text
    • https://cdn.sqhk.co/wedegetuso/Xigreih/need_for_speed_no_limits_vr_download.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4423148/normal_5fd86df8c3998.pdfIn PDF document text
    • http://nafarami.medianewsonline.com/78158489537.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388405/normal_603d431422b0e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460233/normal_5fd837f81d05f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4365539/normal_60036db952fb2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489740/normal_60143a248c977.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off00010b3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B3E 5164 bytes
SHA-256: 7b4064cf38e49262cd70d4cd015468010a82bc383768316050e71a74ab55310d
font_01_sfnt_off00011cda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CDA 10616 bytes
SHA-256: 78b88cbf6f7cc3081ffeb9c119b375b1d06044c603ea2fa65bffa404d2b6c3c6

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