Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4f721637768a924…

MALICIOUS

PDF

65.0 KB Created: 2021-04-16 07:09:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 6b429946ed6196708499937767895728 SHA-1: 1793f1a09722ddeb96eddc78fea4837c0049aeb1 SHA-256: d4f721637768a924d8e679a793d07ea02b2e4982fabbdd4717ca21634b05ff8c
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to potentially malicious domains, and exhibits characteristics of a link farm designed to redirect users. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest an intent to exploit users through deceptive links.

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.dgs-interparts.be/sites/default/files/64751185730.pdf In PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/99368311749.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/zomufajiwadusepa.pdfIn PDF document text
    • https://www.jts.org.jo/sites/default/files/webform/76938035167.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/kafavepovimurajubek.pdfIn PDF document text
    • https://www.afscme65.org/system/files/webform/baxuwobokorexifiri.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/tizagoge.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/40110328039.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/kobovigub.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/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=beginner+piano+hindi+songs+with+letter+notesPDF link annotation
    • https://thesanfordschool.asu.edu/sites/default/files/webform/xumigisapiwonatidokababup.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/97035559296.pdfIn PDF document text
    • https://campusrec.princeton.edu/system/files/webform/putiwokareviwe.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_off0000be54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE54 5360 bytes
SHA-256: 2960c40a40b54d180a9a017b93cfd565071dac370c07c187b8da340d4ba58816
font_01_sfnt_off0000d09c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD09C 10920 bytes
SHA-256: 2eb44824809529d5fe7a9009294fa0d02281bc21415332ded51ffabe6aadff71