Malicious PDF — malware analysis report

Static analysis result for SHA-256 06820f87d407e1c0…

MALICIOUS

PDF

81.7 KB Created: 2021-03-11 21:55:25 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-13
MD5: 61155291fbef9742ba112127c222c4e7 SHA-1: d2f9b00d5510dfaa30558367ee2ea4b5e37c560f SHA-256: 06820f87d407e1c01b9ef4eb5bf2d8ef536e184d6d791c1aeda0ea53e54ea3c3
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, identified as a link farm. The heuristic 'PDF_SEO_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' indicate that this PDF is designed to host numerous links to other documents, likely for SEO manipulation or to distribute malicious content. The presence of ClamAV detection and ML classification further supports its malicious nature. The primary IOCs are the URLs found within the PDF, which point to various disposable hosting services.

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://zajinet.ru/award?keyword=encephalite+rabique+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4446399/normal_6010b4e361cda.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4462714/normal_60300d573c9c1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4474456/normal_600bd386d1bdf.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4445570/normal_5ffd9c4a403f2.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4409621/normal_6008b1a6e3189.pdfIn PDF document text
    • http://wijasagasipode.getenjoyment.net/puded.pdfIn PDF document text
    • https://zigizawinowola.weebly.com/uploads/1/3/4/4/134457077/bekeposit.pdfIn PDF document text
    • https://tidosivapozagul.weebly.com/uploads/1/3/4/3/134390518/2d2f08.pdfIn PDF document text
    • https://petabururumeje.weebly.com/uploads/1/3/4/9/134902787/5643321.pdfIn PDF document text
    • http://tuwasukam.getenjoyment.net/josumosomiralov.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420013/normal_604020a6b9ea3.pdfIn PDF document text
    • http://mofemaruwek.sportsontheweb.net/kakamoxivotexevaxufik.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4499995/normal_60368c8c78bf0.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4366366/normal_5fcefe12f31bb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4405642/normal_5fd287ead101a.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4412593/normal_5feb265dcd8b1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425209/normal_6040633737525.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480904/normal_6042c2ec1d1ea.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4448540/normal_5ff087071dd05.pdfIn PDF document text
    • https://womogidukiwu.weebly.com/uploads/1/3/4/8/134873304/sudopikufe-pivane-xepupufusulugi-delametazuvozaf.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off0001044e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1044E 5288 bytes
SHA-256: d15cacf575ad19a3d0d6121c8f6591d1d83a55d44b5a496df830e0258ddd7be9
font_01_sfnt_off0001163b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1163B 10436 bytes
SHA-256: 853323e0ed62428e49fb918e133b4fb9ebf98bfe78fdeac753ed205448ca2c56