Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a11c397fa123208…

MALICIOUS

PDF

78.8 KB Created: 2021-05-30 05:40:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 03dd0becb0a92929d22923f483b81c4a SHA-1: 987a254171be1c1bff5a7871545ae158008e1b85 SHA-256: 5a11c397fa1232086ac6e19fadd85ea346a6f310d8aff4fde70612c3fc0a8342
156 Risk Score

Malware Insights

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

The file is identified as malicious by multiple heuristics, including a critical ClamAV detection and an ML classifier. It contains a large number of external links, with one suspicious URL pointing to 'vilenefex.ru'. The PDF structure suggests it's part of a link farm, likely intended to redirect users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://vilenefex.ru/strik?utm_term=ejercicios+de+inventarios+perpetuos+resueltos+con+iva
    • https://vopesowe.weebly.com/uploads/1/3/4/6/134638419/mirovigalowuvo.pdf
    • https://fuzakeraza.weebly.com/uploads/1/3/4/8/134848422/rovelo.pdf
    • https://cdn-cms.f-static.net/uploads/4450154/normal_6036e2e25dee7.pdf
    • https://vasigigu.weebly.com/uploads/1/3/4/6/134607878/c09fca7.pdf
    • https://maduzoxunixeg.weebly.com/uploads/1/3/0/7/130775653/d3fe5259.pdf
    • https://pilumana.weebly.com/uploads/1/3/2/6/132683063/luzowo.pdf
    • https://cdn-cms.f-static.net/uploads/4489979/normal_60508cbd75708.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/3ad6c039-af46-44b7-8c03-afa170989dc9/74573711631.pdf
    • https://uploads.strikinglycdn.com/files/3fca0364-cf73-4b38-83a2-58e50af2349c/what_are_the_types_of_text_structures.pdf
    • https://uploads.strikinglycdn.com/files/dce80940-9d85-4698-9f89-66bbc8b71473/dubinozipufoxugus.pdf
    • https://uploads.strikinglycdn.com/files/c867bc5f-e93a-48d5-9771-be1cd79b10a9/wutoboporeg.pdf
    • https://uploads.strikinglycdn.com/files/86a57677-d5d5-41fd-a4c4-30b5f69272c5/how_to_read_walmart_receipt_codes.pdf
    • https://uploads.strikinglycdn.com/files/ae082071-42ba-4019-b043-e77d47b5ee17/wheelocks_latin_workbook_answers.pdf
    • https://uploads.strikinglycdn.com/files/b8df18f3-e936-41d9-9abf-5710e85470b5/53986535966.pdf
    • https://uploads.strikinglycdn.com/files/6cc073ca-7972-4597-93b7-ac08382bc857/minn_kota_power_drive_ipilot.pdf
    • https://uploads.strikinglycdn.com/files/1018cbac-a9e5-4e6a-b17c-48fd34242249/hp_envy_4500_e-all-in-one_printer_review.pdf
    • https://uploads.strikinglycdn.com/files/217cd539-a825-4be6-8c84-ad5814117825/best_app_to_learn_guitar_licks.pdf
    • https://uploads.strikinglycdn.com/files/2c7c8c13-3a17-4666-b839-6a8b906ea113/totumanaviwazurikeze.pdf
    • https://uploads.strikinglycdn.com/files/75d56c89-b7a5-4792-8d3a-45d29bfadc69/97279290686.pdf
    • https://uploads.strikinglycdn.com/files/03a533c2-d1ad-4b86-a3e4-90133db7f0b4/50619895886.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f421.bin
89d0711a50a8fae6b20c5714bab2cd0c66884c40f1c42fb620aabf9803ff4e9c
pdf-font-stream PDF embedded font (sfnt) at offset 0xF421 5160 bytes
font_01_sfnt_off000105cd.bin
5fd8893e075568cc244c5a6c47a2f68ba264f3433ed12e77d76ad2f55831edf0
pdf-font-stream PDF embedded font (sfnt) at offset 0x105CD 11452 bytes