Malicious PDF — malware analysis report

Static analysis result for SHA-256 71cd3fddc45db2f9…

MALICIOUS

PDF

79.6 KB Created: 2021-04-30 22:43:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: dd4425d29c7000fca2cf53ff3f568de8 SHA-1: dcb14a0940022fd5d96a6c1c324037038ce3899c SHA-256: 71cd3fddc45db2f9e4f9a9fb9679859b0750460267e9a234496c289e225e2ad0
186 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as a link farm and detected as malicious by ClamAV and an ML classifier. It contains numerous external links, many pointing to disposable domains, suggesting an attempt to manipulate search engine results or distribute malicious content. The presence of external URIs and the overall structure indicate a phishing or SEO spam campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://jacksth.ru/strik?utm_term=all+the+bright+places+movie+ending+quote PDF link annotation
    • http://cetakchantek.com/the_distance_between_us_charactersn6tiq.pdfIn PDF document text
    • http://fezelegafefuv.mywebcommunity.org/2002_buick_century_radiator_hoses.pdfIn PDF document text
    • http://zdorovienashevse.xyz/how_old_do_you_have_to_be_to_get_social_security_benefitslq9ry.pdfIn PDF document text
    • https://talunijepi.weebly.com/uploads/1/3/4/5/134599753/jupaxafafuruz.pdfIn PDF document text
    • https://kolukofutire.weebly.com/uploads/1/3/0/7/130740340/zoresutumov-fazabepo.pdfIn PDF document text
    • http://lnstagram-verifedbadge.com/minecraft_skin_template_meme3n6j0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378405/normal_60416367cf8db.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4462339/normal_606677902b8d8.pdfIn PDF document text
    • https://mubuzetuwifo.weebly.com/uploads/1/3/4/7/134703000/3e7d54.pdfIn PDF document text
    • http://maykistore.ru/velilikovblkcq.pdfIn PDF document text
    • http://vuzuwul.getenjoyment.net/51600922373.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365586/normal_5fd74107305ab.pdfIn PDF document text
    • http://gebevojika.mygamesonline.org/38324011862.pdfIn PDF document text
    • http://6gusevshop.website/xudapota4b4ky.pdfIn PDF document text
    • http://tapagigozi.medianewsonline.com/karogexagevisodibivufir.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4444366/normal_6037180b17a4c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4428035/normal_6063d3339482e.pdfIn PDF document text
    • https://lomofoxagut.weebly.com/uploads/1/3/4/5/134524577/parunolafemo_pesof_ripeponugewozo_sonojaja.pdfIn PDF document text
    • https://rijopadanag.weebly.com/uploads/1/3/1/0/131070137/2971613.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/a86ef5ec-e5ee-4263-aadf-69c4c5d6d215/40359572534.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1820847f-f655-493d-a33c-93194501c8e0/60006237729.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6165e74b-ebef-41f1-a5c7-e23addd9d155/what_qualifies_as_wrongful_termination_in_california.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/303cc3d1-7f93-4d18-862a-a4109a9c6269/jatinerituwosaju.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/39b9e05f-134e-4f3b-9753-5226ce94107f/vitatewoziponam.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6bcb0712-761e-4084-bdc6-b61fece9da3f/88762718808.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/51506bfd-7266-4c2b-b035-e17460484c86/geometry_regents_reference_sheet_2019.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f163525a-f41d-46fa-b905-533fec0be973/quadratic_equation_word_problems_with_solution_and_answer.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6b9747d2-00ad-4f79-ba61-a9d3978cad9f/1126101611.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_off0000f78b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF78B 5800 bytes
SHA-256: ed75ed35e9d9331eced9e6963e0a9e003e6299fdafacaff6f4d42fb9b6fd4f9f
font_01_sfnt_off00010b1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B1D 10576 bytes
SHA-256: d274635ecdd6f5d0798c304b23de96a3f706b022603c25cacf1b4d5a4e78c358