Malicious PDF — malware analysis report

Static analysis result for SHA-256 835de6ef77459300…

MALICIOUS

PDF

81.6 KB Created: 2021-04-15 16:50:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 9acd2de83609bef9b56e8f4667d4a3dc SHA-1: fb5abaa18339f95f406447c9385bef244fa18be2 SHA-256: 835de6ef77459300a0faa7f880c739a6cd380565ab922dc05b9885d2b50e3b46
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, many pointing to disposable domains, and is flagged by ClamAV as Pdf.Phishing.Trojan. The ML classifier also strongly indicates maliciousness. While no scripts were explicitly extracted, the PDF structure and link farm heuristic suggest an attempt to redirect users to malicious sites, likely for phishing or malware distribution.

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://ambrose.edu/sites/default/files/webform/49323480199.pdf In PDF document text
    • https://www.termis.org/system/files/webform/98565071062.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/61391242106.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/netugapufuzutazegiwiwivi.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/zasadavatemomafupe.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/subeditanutojodojewogize.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/55178968397.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/pakajumotarowumomudiro.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/dadesiludidogujuta.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/gurolaxi.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/zomosazufexebale.pdfIn PDF document text
    • https://europa-ts.ru/sites/default/files/webform/totikejeropisatuzubafaba.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/6659556688.pdfIn PDF document text
    • https://www.termis.org/system/files/webform/manejuwavujegajejumoxak.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/ngfLrbzwjls/uplcv?utm_term=best+video+game+for+ps4+2020PDF link annotation
    • https://community.princeton.edu/system/files/webform/wijudabopijobomoxusosul.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_off0000ff8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF8E 5800 bytes
SHA-256: bdc42634aa09f611be2279d7694c810fb77771ee04c16e3f55aace680b17b739
font_01_sfnt_off0001134b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1134B 10608 bytes
SHA-256: 7a6371be8aef0471d173e5399003a87e44abf48e2d720fb16dc1a6cc85a843bf