Malicious PDF — malware analysis report

Static analysis result for SHA-256 c81430fa3d16e22c…

MALICIOUS

PDF

72.6 KB Created: 2021-04-08 19:18:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: fec7cc1dcd7c078a7cf32495968846c3 SHA-1: 2098e0067855d738ad2bc1657c3f4d560a3ecee9 SHA-256: c81430fa3d16e22cfc7a18c0efc4cdb05623418257bc9869b8c5f9d85469d081
126 Risk Score

Malware Insights

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

The file is a PDF that contains numerous embedded URLs, many of which point to disposable or unknown domains, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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 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://www.termis.org/system/files/webform/nibobuzokojovafizuza.pdf In PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/50635107556.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/65827293628.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/58234525485.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/todoxobolukajit.pdfIn PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/xikamiwaboloz.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/87400145234.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/ponezilineg.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/fifomibap.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=banjo+chord+sheet+pdfPDF link annotation
    • https://lib.asu.edu/system/files/webform/vabomabexajamoja.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/juvuwudonuvusenovirem.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/66140853426.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/83401752781.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/vujipudujusikal.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d294.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD294 5076 bytes
SHA-256: 3cab242b259090f0a734e70dde637e06a9a0d07a9b8b14f28d3708398e7182cd
font_01_sfnt_off0000e3ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3CE 10524 bytes
SHA-256: 005a8d75398f859e8b748c0f2a7d515ff411c76d05ecc04d86d709399db6e9af
font_02_sfnt_off000107b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107B7 4324 bytes
SHA-256: 1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e