Malicious PDF — malware analysis report

Static analysis result for SHA-256 671c59fd98bfcfba…

MALICIOUS

PDF

79.3 KB Created: 2021-04-07 00:24:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: 91b1dc77b76a7123de6db6192d7faa78 SHA-1: c0fd239da054e5d173488edccd7b6aeae63368e5 SHA-256: 671c59fd98bfcfbaed65543f0eaf31021c651ac80da3575f42beab46ee8e19c7
186 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 disposable domains, suggesting a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://vilenefex.ru/award?keyword=robust+nonparametric+statistical+methods+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4486521/normal_60181c19cb9e9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495385/normal_604fe1215ce00.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393020/normal_5ff3c866b3435.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4377401/normal_605bbbe6f1a0c.pdfIn PDF document text
    • http://submonster.xyz/20738649916v28m8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380214/normal_5fd136245843d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4474191/normal_600b965b035c6.pdfIn PDF document text
    • http://vash-fasad.live/guitar_hero_rock_the_80s_wikiasjrj.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476930/normal_6015b24d3634d.pdfIn PDF document text
    • http://pmaider.com/converter_jpg_em_smallpdf4ozu8.pdfIn PDF document text
    • http://graatorama.space/80151019014o9ayl.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450502/normal_604d15b314b8c.pdfIn PDF document text
    • http://stakingyfi.com/wuliletowafisafutuislbc.pdfIn PDF document text
    • http://bilenilabokadox.22web.org/3450705741.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://5d3a3edc-1384-4eb0-a354-174dd54c13aa.filesusr.com/ugd/7f5dc5_eac8bcee77e04d148ff9a6afd1eb96af.pdf?index=trueIn PDF document text
    • http://valolezame.epizy.com/14670096615.pdfIn PDF document text
    • http://duginefasozuna.rf.gd/como_fazer_ficha_de_leitura.pdfIn PDF document text
    • https://d7ae471b-a447-437d-81b4-4e603f8679d9.filesusr.com/ugd/0a3240_0082082fe51d4c7fbbb408fbb3c2eeb0.pdf?index=trueIn PDF document text
    • https://7648721b-06f4-4917-9c2a-921156fbbd07.filesusr.com/ugd/a7266c_d643b4e2daff4fe992e786f8e72221a9.pdf?index=trueIn PDF document text
    • https://3dbd840c-7861-42b4-b064-af52d1d2f4eb.filesusr.com/ugd/86319b_8e7708b164bc431e9589df8378f0d06c.pdf?index=trueIn PDF document text
    • https://36622f5a-5a1b-41a5-aa98-965156e47ac2.filesusr.com/ugd/804ff6_c6efaf7fc4f14e2db29078bf742ba1a8.pdf?index=trueIn PDF document text
    • http://bigefen.rf.gd/40894932990.pdfIn PDF document text
    • http://relipig.epizy.com/adjective_order_practice.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_off0000f61e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF61E 5540 bytes
SHA-256: 2f04f65bb46b95172a431ae8e4a449af51629cf4b2d1ecbdc0b7fe93e302d3a5
font_01_sfnt_off000108c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108C0 11268 bytes
SHA-256: 044ffb621980b73e3a1c5dc79db4737d1ac3be5eff5eab42c3bb9fc11e0e00ba