Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c8fbb81e62c9a3d…

MALICIOUS

PDF

85.8 KB Created: 2021-05-30 03:47:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: d08e8371e691936616de00133175e59d SHA-1: 543cdd403dc41b77d3c754f6213e8db36b270c10 SHA-256: 4c8fbb81e62c9a3d8492c157b5bb798b61f834bbe8fda901e621d60c30fee270
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://mezovuduw.ru/strik?utm_term=nouvelle+grille+salaire+fonction+publique+hospitali%25C3%25A8re+2021 PDF link annotation
    • https://xezinazilasiza.weebly.com/uploads/1/3/4/3/134319357/bunubenemi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4392658/normal_6039a61a30063.pdfIn PDF document text
    • https://ganunobagitap.weebly.com/uploads/1/3/4/0/134012575/nivixebidopabi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465392/normal_60225d92ecd61.pdfIn PDF document text
    • https://bilewazivabo.weebly.com/uploads/1/3/2/8/132816117/1eac134.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459777/normal_606883cde324a.pdfIn PDF document text
    • https://xaberekulokoka.weebly.com/uploads/1/3/1/8/131856377/1190451.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4378153/normal_5fc5734e49971.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4392860/normal_6033a3ed20b9c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465123/normal_6012fa5aea5b5.pdfIn PDF document text
    • https://duveniwapawas.weebly.com/uploads/1/3/4/2/134265961/5668844.pdfIn PDF document text
    • https://nolutoxut.weebly.com/uploads/1/3/4/6/134683805/6974483.pdfIn PDF document text
    • https://tuwubave.weebly.com/uploads/1/3/3/9/133997869/7028252.pdfIn PDF document text
    • https://jurogewogil.weebly.com/uploads/1/3/4/3/134318518/gigibasu.pdfIn PDF document text
    • https://dubasebajulux.weebly.com/uploads/1/3/1/3/131382081/4676626.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379240/normal_605a23b981ce1.pdfIn PDF document text
    • https://fujikoxeloto.weebly.com/uploads/1/3/5/3/135307408/xutafofunoviw.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/f7224e2f-1008-47eb-a79f-ab544ea0fc67/strongs_hebrew_bible_dictionary.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4b5aef28-e3d8-4bd8-97b7-aa1ec141a52b/use_pascals_triangle_to_expand_the_binomial_calculator.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/570e708c-442d-443f-be7e-8f2e24e4ac32/liftmaster_3800pld_smart_control_panel.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d424082f-2a0b-43ba-8c22-ed4d5a9add0a/dopotasojuwododi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cbef8233-8307-492e-a6c6-91a623b1bf8b/watch_pride_and_prejudice_2005_online_free_fmovies.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fda9b897-37fe-4cd5-96be-63646ddd7743/49367820209.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7809fc33-3658-4cfb-adce-a34c3cd26db5/organizational_structure_definition_business_studies.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/86f10276-d5fa-4f7f-90aa-6fd6bbb7b3e4/monuxifunofetipijafozipi.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_off000108f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108F4 6040 bytes
SHA-256: d1e6a1b91b9a27fc4b73074395ee70910908dd08a826e59e25efc47ebf150e1d
font_01_sfnt_off00011d56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D56 12844 bytes
SHA-256: a73c7ce487730fde01ffab7f89594aa3541a9a7cb3e50fc00c54c8d8cbd483fa