Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c4ac91647714595…

MALICIOUS

PDF

79.4 KB Created: 2021-03-18 11:29:51 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: d0ae64b9cd515c68f6e79c2618610226 SHA-1: 28378b8585076cdca06387d0b82b2b63b4981d39 SHA-256: 8c4ac91647714595c48bc8cf6a0224cfa4eb96029c9504700fb11e89ba47e326
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external URIs, many pointing to disposable hosting, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the presence of embedded URLs and the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggest the document is designed to redirect users to malicious sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://midufefew.ru/award?keyword=biosynthesis+of+cholesterol+pdf+download PDF link annotation
    • http://gta-msk.ru/53638371346j2470.pdfIn PDF document text
    • http://price-list.moscow/frame_sentence_on_monstrousxeszv.pdfIn PDF document text
    • http://confirmationhelpcenter.com/addition_worksheets_for_grade_3gg6lz.pdfIn PDF document text
    • http://usacreditmonitoring.info/bavupotq5me.pdfIn PDF document text
    • https://depularo.weebly.com/uploads/1/3/4/6/134601330/nubitepe-xofuka-betevibexeruzuj-wotuvutiviz.pdfIn PDF document text
    • http://pmaider.com/libros_de_economia_gratis_para_descargarz0s5o.pdfIn PDF document text
    • http://copyrightproblem.com/932065355799xftl.pdfIn PDF document text
    • https://fimulumalopa.weebly.com/uploads/1/3/5/3/135326017/4703663.pdfIn PDF document text
    • https://gezumadugoviful.weebly.com/uploads/1/3/4/6/134611133/3871259.pdfIn PDF document text
    • http://idealicaitalia-ufficiale.site/moment_format_cheat_sheetswm6q.pdfIn PDF document text
    • https://jebapawobukil.weebly.com/uploads/1/3/4/5/134521284/surajumizi-zideseloj.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480728/normal_60415f77a80e8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378167/normal_603cc515c1511.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485935/normal_603149cf728b5.pdfIn PDF document text
    • http://store50off.info/pampered_chef_rockcrok_pork_recipesgxssd.pdfIn PDF document text
    • http://leftoutclub.com/how_to_replace_a_smoke_detector_thats_hardwireds4kyt.pdfIn PDF document text
    • http://autolombardpro.ru/navy_non_technical_jobsukuoy.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/fonazuzixagizir/sulivojome.pdfIn PDF document text
    • https://a7176590-a44a-43b4-8b25-1171fb6190ac.filesusr.com/ugd/e6ccb8_b39ac537fdc34d3eaa427fc7c816bded.pdf?index=trueIn PDF document text
    • https://76bf09fe-c378-4d6f-baa9-beaf48595a8b.filesusr.com/ugd/61567a_a5f63962042c4cc5bda7026908362552.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/pesetufavo/reliability_centered_maintenance_implementation_made_simple.pdfIn PDF document text
    • https://s3.amazonaws.com/jeworurowam/how_to_demonstrate_critical_thinking_in_nursing.pdfIn PDF document text
    • https://98e80eac-0673-4bf9-a3de-4132461903b3.filesusr.com/ugd/1acd69_a011c347e2ae4d71beda0ea8be974105.pdf?index=trueIn PDF document text
    • https://52a72965-a6d2-471e-b66a-59a59a4d663b.filesusr.com/ugd/e643da_bd9d106f727c4786a152d3933e5df3d2.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f829.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF829 5484 bytes
SHA-256: 5d129f8bac98e420a1d7b812a1701149bf00e14f7569c0daa2f756e38d261513
font_01_sfnt_off00010ae9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AE9 10972 bytes
SHA-256: fb2936eb99298861e8a826e942fd7be24556e3a2459444d7fbc9a354621240cb