Malicious PDF — malware analysis report

Static analysis result for SHA-256 811f403f9669cb34…

MALICIOUS

PDF

74.7 KB Created: 2021-03-25 08:22:46 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: c8f44b27998d9edc599042109b856c58 SHA-1: b4eca0f3dbd64dec3999dbecbb90be95f41cbe45 SHA-256: 811f403f9669cb3465c6ac9b41ba604c064483325abd81330b896d18dac24f02
244 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to disposable hosting or known malicious redirectors. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or redirecting users to malware. The document body is heavily obfuscated and contains metadata suggesting it was generated by wkhtmltopdf, not a typical user document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://crophysi.ru/wix?keyword=defensa+civil+colombiana In PDF document text
    • https://cdn.sqhk.co/xotakuzazuf/dnhcigc/formula_for_area_of_a_square_based_pyramid.pdfIn PDF document text
    • https://cdn.sqhk.co/dutudovajud/dhdgc5P/digital_marketing_agency_near_me.pdfIn PDF document text
    • http://jaralet.getenjoyment.net/62930331067.pdfIn PDF document text
    • https://gozerivolese.weebly.com/uploads/1/3/4/2/134265833/8450623.pdfIn PDF document text
    • https://cdn.sqhk.co/womafafowix/iichj36/47684446191.pdfIn PDF document text
    • https://nidedijuba.weebly.com/uploads/1/3/0/8/130814831/70717cc69fe713.pdfIn PDF document text
    • https://dezekebewefe.weebly.com/uploads/1/3/4/7/134731304/079baa3bd3ce.pdfIn PDF document text
    • https://cdn.sqhk.co/vepanoxubere/gfKhggi/70022568197.pdfIn PDF document text
    • https://mobakuwi.weebly.com/uploads/1/3/4/4/134404075/bogali-ridulojuk.pdfIn PDF document text
    • https://vuzejugusu.weebly.com/uploads/1/3/4/4/134486163/437c7e.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/813b2650-7ef6-4efe-aaf5-663e3452162e/hp_folio_9470m_price_flipkart.pdfIn PDF document text
    • https://s3.amazonaws.com/pexodugosa/34322372936.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0fb13ac3-9062-4d2d-a5e3-b50bc0c3605c/contemporary_sport_management_4th_edition_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a6d210ee-25af-4f23-b482-27ccd2cb38ae/weed_eater_lawn_mower_parts_manual.pdfIn PDF document text
    • http://sukokovevaz.atwebpages.com/avogadro_s_gas_law_problems_and_solutions.pdfIn PDF document text
    • https://s3.amazonaws.com/mudurixo/dupawisati.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c7e972c2-a859-427f-9a33-485a0f06e42d/data_structures_interview_questions_and_answers_for_freshers.pdfIn PDF document text
    • https://s3.amazonaws.com/fomaralunex/73042499066.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/04290b5d-b144-46bf-8fa2-aad99e20db2a/stihl_battery_edger_review.pdfIn PDF document text
    • http://wazipegemezen.atwebpages.com/macam_macam_abnormal_gait.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3c6438ea-298f-443d-b291-cdb8b830a6d6/why_does_my_oil_central_heating_smell.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dd0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD0E 5132 bytes
SHA-256: 773fd2d85513d7dbd0412cca717ece868fa24cea0ade1f29acd1a0b639913e0f
font_01_sfnt_off0000ee81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE81 1740 bytes
SHA-256: 8b3e0007e4859c637632ff00cab5861c38b943db86b102f7f8f9246f23a004fb
font_02_sfnt_off0000f702.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF702 11572 bytes
SHA-256: e39eca64b98885e663f93c5c3904d4b5a3c168ff30496f1f7b32a39a8473607a