Malicious PDF — malware analysis report

Static analysis result for SHA-256 4719af852c7d0c05…

MALICIOUS

PDF

73.3 KB Created: 2021-06-08 20:12:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 31681f798af3aed20fe60b664f6ec385 SHA-1: 9212861912befe6d3db61a0f1e43da82389ef34c SHA-256: 4719af852c7d0c05614ca62d5ce81d92fe047b8ab30ae935128f20f4e422edcf
156 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 by the PDF_SEO_LINK_FARM heuristic, pointing to various domains. One prominent URL, 'https://cructi.ru/pbw?utm_term=prefer+would+rather+worksheet+pdf', is directly embedded and likely serves as the initial lure. ClamAV detection and ML classification strongly indicate malicious intent, classifying it as a phishing trojan. The primary attack pattern involves redirecting users through a link farm to a malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 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.
  • 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://cructi.ru/pbw?utm_term=prefer+would+rather+worksheet+pdf PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4416790/normal_5ff21d70b5426.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376354/normal_6018483069425.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4447877/normal_600337f3a53b2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454287/normal_604cc5c01d361.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366302/normal_605048a0498d7.pdfIn PDF document text
    • https://gimipozadifan.weebly.com/uploads/1/3/1/3/131380487/7136424.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4391899/normal_5ff712c42c654.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391302/normal_6053827bb9f46.pdfIn PDF document text
    • https://kumigovujubexug.weebly.com/uploads/1/3/0/7/130776874/9114824.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/c2ab0d38-027b-44ee-944e-00dbcd1967e0/corsair_commander_pro_installation_diagram.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e812fc1e-2515-417e-89d3-433b20466cc5/the_art_of_effective_communication_-_tony_robbins.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ffa2e018-51ca-4b68-a431-57ae5d7e5209/23821072618.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/083e7baa-7fcd-4aa7-bd42-2c82c8374347/dyson_v6_animal_cordless_vacuum_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0f9b7ffb-d238-4818-9040-048d248318ee/cours_apiculture_gratuit.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bf175425-73ce-47c3-ac79-c4555a6b1e8d/roland_micro_cube_gx_reddit.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/32492cf8-3b89-4c5b-8864-0c48749a191b/juwaragimofuribuf.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2bea15ac-71f1-430e-a536-0f258aee4f1f/pakukuwedokusogikurutiti.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/db09ff72-931e-40bf-a06f-a825d8921771/how_to_do_road_to_hana_on_your_own.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_off0000dc95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC95 5288 bytes
SHA-256: d500f263f61d1342ef9fc7fe59386186aa29ccf962182003127096209acb65ce
font_01_sfnt_off0000ee98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE98 12340 bytes
SHA-256: edc95510bfe39a4465c832f062fa8cc296138ea4ce8d80d303f63b3bb11b127a

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