Malicious PDF — malware analysis report

Static analysis result for SHA-256 9bb3411e6335be18…

MALICIOUS

PDF

71.5 KB Created: 2021-03-17 15:13:08 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 712151d750c2c770b55344f4bcd66a73 SHA-1: bbd150909c0b62aee426b572c77b3b8e9099e9e4 SHA-256: 9bb3411e6335be186bcce876fabe37c08bbc9a74653ea3641a9cc3ffae079c8d
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, identified as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO manipulation. The document body is heavily obfuscated and contains metadata from wkhtmltopdf, suggesting it was programmatically generated to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://kuzutuzo.ru/123?utm_term=banjo+bappa+song++mr+jatt PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4496165/normal_600bc8e89e8a6.pdfIn PDF document text
    • http://danixoxixofizi.iblogger.org/bomba_calorimetrica.pdfIn PDF document text
    • http://devivitonewe.sportsontheweb.net/attach_files_online.pdfIn PDF document text
    • http://rigudozefogo.mypressonline.com/wezazukawa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4502920/normal_6033aadeb7646.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414849/normal_5fd2e656024a5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488569/normal_6011c66bbb6ed.pdfIn PDF document text
    • https://jegolufu.weebly.com/uploads/1/3/4/6/134677495/640041a144df3.pdfIn PDF document text
    • http://wusozupu.mypressonline.com/panasonic_microwave_oven_nn-sc668s_reviews.pdfIn PDF document text
    • https://vumizopefi.weebly.com/uploads/1/3/5/3/135313358/vokirubisilarukinom.pdfIn PDF document text
    • http://rezokivi.medianewsonline.com/54206077476.pdfIn PDF document text
    • https://gisimezibeze.weebly.com/uploads/1/3/0/8/130874543/6159854.pdfIn PDF document text
    • http://votixibutiro.medianewsonline.com/irregular_preterite_verbs_spanish_examples.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://367e539a-c541-4439-991c-4bf2bef2aa7a.filesusr.com/ugd/77d535_961d97d58fd74db09a604388cc39b88e.pdf?index=trueIn PDF document text
    • https://1b6fe947-be7e-4494-9a94-f566f178d3d1.filesusr.com/ugd/89064d_b2570d48a25b4ee6bc7537a77eb008e6.pdf?index=trueIn PDF document text
    • https://dedb376b-efc3-4528-ac10-fc65d12f866c.filesusr.com/ugd/5f6074_d35dccf63f7e4162a63469a34d7ab96f.pdf?index=trueIn PDF document text
    • http://tifilow.onlinewebshop.net/shimano_r2000_reel_parts.pdfIn PDF document text
    • http://kobitosen.epizy.com/fonumujoderisibu.pdfIn PDF document text
    • https://2a4065d7-883d-43e8-a524-7ce9aa4b4e88.filesusr.com/ugd/ccb1c6_988da3e115cd4b44a51d92aec6d3b4eb.pdf?index=trueIn PDF document text
    • http://dibulokesimerog.rf.gd/93926381324.pdfIn PDF document text
    • http://kewevagisugimuw.onlinewebshop.net/duxamipanororefunomebu.pdfIn PDF document text
    • https://5a8aee2d-3d68-4c09-98ed-743c9c56d6fd.filesusr.com/ugd/460efe_8abfe2e337b34a8b8bfaf08511f0741b.pdf?index=trueIn 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_off0000cede.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEDE 5372 bytes
SHA-256: a783e51afcfbbd116371f1190797de700c2a660c3e1c3fb6e4fe71045deda623
font_01_sfnt_off0000e10c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE10C 2024 bytes
SHA-256: 5d59e80714f055d0e20d1c4ed594903f00ea25dd365ddc0e243c90ca16be52db
font_02_sfnt_off0000eaa4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAA4 11028 bytes
SHA-256: 1d92ab18864b4d321ad7d0335c8165e86cd854a066139603584e7c82796c6c86