Malicious PDF — malware analysis report

Static analysis result for SHA-256 a909d6d557c7232c…

MALICIOUS

PDF

81.8 KB Created: 2021-06-10 13:45:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: ae045085b4be52a6c3b381d05bed6c69 SHA-1: 540e663442f78fb053ef5e16c29f5cbc0010201d SHA-256: a909d6d557c7232c233802c0a08d3f7b65cc2272f177b8795a8950de78a08ca2
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many pointing to disposable hosting, suggesting a link farm used for phishing or malware distribution. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a date, but no clear instructions or lures are discernible from the readable text. The primary attack vector appears to be directing users to external URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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://dugedepap.ru/123?utm_term=capitulo+3b-+3+realidades+2+answers PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4465250/normal_60600a98547e3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4372753/normal_60c12095a0234.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4418557/normal_5fff0a9394be9.pdfIn PDF document text
    • https://bifutizuwosedi.weebly.com/uploads/1/3/4/6/134645412/55e7a0c5d0bd59.pdfIn PDF document text
    • https://xosizinunebazen.weebly.com/uploads/1/3/4/0/134017923/01e0b18fe93.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://pukagij.pbworks.com/w/file/fetch/144468531/tesijug.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/62cf5e1f-7052-4865-ab3e-85f4230dc1d6/nizunijuku.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a8cef806-90eb-4777-bdf2-c5824ddcabb5/what_does_a_power_distribution_engineer_do.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/14a47bf1-1efa-4a74-a716-6dfef713dad4/windows_2012_server_iso_free_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/373ce8fc-7eb1-4ba8-a7d2-06ac7f4a9147/jelubakijebekuwekovogiv.pdfIn PDF document text
    • http://sufasujozu.pbworks.com/f/46656193879.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c3d1c561-e80f-47d3-96dc-f6610b794f6e/what_is_sweat_equity_in_real_estate.pdfIn PDF document text
    • http://rugewenuzed.pbworks.com/w/file/fetch/144742143/verification_of_kirchhoffs_current_law_lab_report_discussion.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9c65eba2-fbf6-40b0-8749-b52a6819a742/batidora_kitchenaid_professional_600_manual.pdfIn PDF document text
    • http://pilujibos.pbworks.com/w/file/fetch/144500757/safety_first_car_seat_installation_rear-facing_seat_belt.pdfIn PDF document text
    • http://ditidema.pbworks.com/f/68660785129.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e517f066-f8e1-47ad-a39d-0d644c787550/mapa_principales_placas_tectonicas_del_mundo.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_off0000ff29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF29 5420 bytes
SHA-256: 54047ad7c5b77b5e1bb951e7e7c0441bdf52dc3e71ef717e240e5c0eb440d136
font_01_sfnt_off000111af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111AF 11528 bytes
SHA-256: f73f3ca7e77109e7f497432dbda72e84fd38825d53390be51269d60805bbc71d