Malicious PDF — malware analysis report

Static analysis result for SHA-256 9e8d86d59db17c82…

MALICIOUS

PDF

76.3 KB Created: 2021-04-13 23:53:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: f8986892852325600090ab68871a800e SHA-1: 7713becac9fcd5b38c20f373dc6f835d8a67219b SHA-256: 9e8d86d59db17c827108f6c830b3084d339f2345c5ecd494eaba8f78719827a6
126 Risk Score

Malware Insights

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

The PDF was flagged by ML and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external domains, many of which are hosted on disposable domains. While no scripts were explicitly extracted, the PDF structure and link farm behavior suggest an attempt to redirect users to malicious sites, likely for phishing or to download further payloads.

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://www.ofalloncasting.com/sites/default/files/webform/68406293253.pdf In PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/34869944823.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/27017481005.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/jokefogebefuzifuzew.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/26688185713.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/nunemoxajusadokuxilebe.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/dalobasowi.pdfIn PDF document text
    • https://www.dgs-interparts.be/sites/default/files/xufatonapa.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/fudigebifofonixetizitalu.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/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=how+to+win+at+mancalaPDF link annotation
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/68876097481.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/42655509772.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/libovonudipiguriteg.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/78922999772.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_off0000f076.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF076 4724 bytes
SHA-256: ca1cd7e99a935c6f4f837624e37622706afdeb35b1cb400e4d539d7c789a7a41
font_01_sfnt_off00010085.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10085 10604 bytes
SHA-256: 2182c8afeb88ea5c5a84c5c72e6587d89a735e7c5c0ecec7565560c82e43cecd