Malicious PDF — malware analysis report

Static analysis result for SHA-256 9167dbeffeb6521a…

MALICIOUS

PDF

74.3 KB Created: 2021-04-06 19:14:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: d11942707263c0e27fb7614dc0cdf93e SHA-1: de0425fbcea52dbffd52711c48ed14cf5ef8113b SHA-256: 9167dbeffeb6521af54b7b214ebe6419cd5720bcad3defaea4586108d5bf6a29
126 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high probability of malicious intent. The PDF contains numerous embedded URLs, many pointing to disposable or unknown domains, suggesting a link farm or phishing lure. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior. While no scripts were explicitly extracted, the nature of the embedded URLs and the 'ML_NYX_PDF_MALICIOUS' firing suggest the PDF is designed to redirect users to malicious sites, likely for phishing or further payload delivery.

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 http://oaklandchildcare.org/sites/default/files/webform/zomosazufexebale.pdf In PDF document text
    • https://ambrose.edu/sites/default/files/webform/seliruni.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/zasadavatemomafupe.pdfIn PDF document text
    • https://www.mainephilanthropy.org/sites/default/files/lipedoketuparukol.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/41266633523.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/94808830073.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=komplikasi+atonia+uteri+pdfPDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/68272747422.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/bidemuf.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/46273532178.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/mizol.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_off0000e60c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE60C 5220 bytes
SHA-256: 8957f479476dc9e7d841a5512985cc2466283b9a501d8bb287162de24160f3d8
font_01_sfnt_off0000f7b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7B1 10720 bytes
SHA-256: 77c80b9484afd8857bd2518441cc4aad543c35f4e37eae71fb154f79395d5d4c