Malicious PDF — malware analysis report

Static analysis result for SHA-256 21af6e3ade8aa7c3…

MALICIOUS

PDF

74.9 KB Created: 2021-05-30 01:07:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 07b2f22e9b47d09886a187c76a8e2218 SHA-1: 8db4f103a013b3e7ab04a6b9f094e445b600923c SHA-256: 21af6e3ade8aa7c3431f300b3d29732e608d08a0823575fdd9a8876b96157251
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains a large number of external links, suggesting it functions as a link farm, potentially for SEO manipulation or to host phishing content. The presence of embedded URLs and the PDF_SEO_LINK_FARM heuristic strongly support this attack pattern. No scripts were extracted, but the nature of the embedded links points towards a phishing or malicious redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://golowaki.ru/123?utm_term=2+decimal+places+worksheets PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4369638/normal_5fd6738003b5f.pdfIn PDF document text
    • https://xerirexu.weebly.com/uploads/1/3/4/5/134592073/katigejofina.pdfIn PDF document text
    • https://mafizawejibon.weebly.com/uploads/1/3/1/3/131383772/1f8a4c01d027549.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4455376/normal_6004faf038906.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4503533/normal_5fedab9bc1bf2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4402519/normal_5fda64c42993a.pdfIn PDF document text
    • https://fasitidepev.weebly.com/uploads/1/3/4/3/134312072/pegibidumadosab_sivutata_duzodobanima.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4467975/normal_60b01e8609576.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4472793/normal_603cea82d6b3f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4403262/normal_5fcf1ca266ad5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4418199/normal_605cdeb971e3f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483855/normal_601cacfc0f491.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450513/normal_6065935a14173.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4473047/normal_6009ac51a344e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488809/normal_602dff7d0e8dd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387718/normal_605f9805e1acc.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4502246/normal_60b2b2e69453f.pdfIn PDF document text
    • https://guvolobojifo.weebly.com/uploads/1/3/4/7/134733869/9096357.pdfIn PDF document text
    • https://jofexudu.weebly.com/uploads/1/3/5/2/135295173/4619cd8f.pdfIn PDF document text
    • https://foralesu.weebly.com/uploads/1/3/4/0/134096101/9eb5ec46dfaa.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_off0000e668.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE668 5504 bytes
SHA-256: 01082387ccbfff9b25297894315157c829a9cd0723c0b3442b2059dee9c70a24
font_01_sfnt_off0000f8ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8FF 10932 bytes
SHA-256: 8f9c605d799ee4a03d7e627d1c007bf221d6931d2bdc56e02dd0f47b1b686979