Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8088a4628fdc82e…

MALICIOUS

PDF

78.5 KB Created: 2021-04-26 16:23:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 4f66a8ea1b164177d3f160d4193d8ec1 SHA-1: 038ed7d18ba476757d0b55ad2113e6a1bb0f59c1 SHA-256: a8088a4628fdc82e28ad7da59a27b1f91bf15f1249130cc383ca25d151e2aba9
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. The document contains numerous embedded URLs, many pointing to seemingly legitimate domains but serving PDF files, suggesting a link farm designed to obscure malicious intent. The presence of external URIs and the overall structure indicate a likely attempt to redirect users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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 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://architecturaldesigninc.com/sites/default/files/sujuxot.pdf In PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/dutaberapowuniz.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/85322732160.pdfIn PDF document text
    • https://www.clinicasfantamaria.ro/sites/default/files/webform/33767122539.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/58994315224.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/30199048500.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/52499587618.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/tojawi.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/nukuromenalifaru.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/11252708720.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/rebunedirewe.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=fifty+shades+of+grey+movie+vs+bookPDF link annotation
    • https://lib.asu.edu/system/files/webform/98562832035.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/97035559296.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/65601020807.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_off0000f2a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2A9 5612 bytes
SHA-256: 2cfc71f37ee13bd09477cb57f1b7c716697658161b3564cf1333702fe9c170f1
font_01_sfnt_off000105ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105AD 11648 bytes
SHA-256: 2b20859b861dad692cba6240650ddfdb76efb8dc136997bf3e4031b589807166