Malicious PDF — malware analysis report

Static analysis result for SHA-256 a44c27d747f5a5a3…

MALICIOUS

PDF

70.7 KB Created: 2021-06-08 17:07:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 7b1340fc599ff08848e39de3df8069a0 SHA-1: ce76c6517ee1e4dc457acb97b0c8f985de47adf2 SHA-256: a44c27d747f5a5a376bd0416157b496c0bc9997f49de1966c4c2eed8129e9736
186 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, identified as a link farm, with one prominent URL pointing to a suspicious domain. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or SEO manipulation. Although no scripts were explicitly extracted, the PDF structure and embedded URIs suggest it's designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://synerhu.ru/pbw?utm_term=tetris+battle+unblocked PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4495244/normal_6023d953c41b8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4486548/normal_5ff043b1da9db.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4424010/normal_5febec81f2840.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426812/normal_5fd9ae606962f.pdfIn PDF document text
    • https://tozuriko.weebly.com/uploads/1/3/1/4/131437247/1650566b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4410985/normal_601e95fb1b556.pdfIn PDF document text
    • https://tabetigilazewa.weebly.com/uploads/1/3/5/3/135392987/kabuzebobitetat.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369504/normal_5fe4cffd6e504.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379374/normal_601f6f9d2021d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4461505/normal_60109b626e420.pdfIn PDF document text
    • https://zepifuvuxetota.weebly.com/uploads/1/3/6/0/136095774/7982298.pdfIn PDF document text
    • https://dugizade.weebly.com/uploads/1/3/4/4/134442098/bf6b056507d589.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/32efc7c0-3347-4263-aaa3-231bb4903b34/fitness_basic_beginner_routine_reddit.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fb88c2f6-f94e-41ab-b68d-2e1ba0ad98e7/medical_surgical_nursing_ignatavicius.pdfIn PDF document text
    • http://mosutit.pbworks.com/f/73911285380.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f53469f8-1b8a-4063-bdda-57a6039975e2/71544613781.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b65b5f51-f0ee-455e-a386-00498377806a/76705762311.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3a5c232a-4a75-497a-8292-ebd11318a9c9/feroferetanaxemanibizef.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/442590a8-96cf-4a16-bb78-70c51df80fe0/30-36_months_milestones.pdfIn PDF document text
    • http://werinenimuta.pbworks.com/f/zombs_royale.io_unblocked_6969.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_off0000d66d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD66D 5088 bytes
SHA-256: d1380a0efad4d5b869339173b031597720c244aefad0ce975deefe6a8a684593
font_01_sfnt_off0000e7c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7C1 10636 bytes
SHA-256: 66f44e0a3f490547c936d900ea9248ce56bac5d7910f3c764009baa5df79193f