Malicious PDF — malware analysis report

Static analysis result for SHA-256 9fdb03419f9e1ffe…

MALICIOUS

PDF

75.1 KB Created: 2021-04-17 03:49:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 2738b114db2fd3e2ca0435254a2f5461 SHA-1: d0245db4a3544bc6070145b6267f7bc92dc8e759 SHA-256: 9fdb03419f9e1ffe4932a706a6203e1c5bdccef6f6ce4bcc21a93fe33ae4253a
126 Risk Score

Malware Insights

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

The PDF contains numerous external links, with the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicating a potential link farm on disposable hosting. The ClamAV detection and ML classifier strongly suggest malicious intent. While no scripts were explicitly extracted, the presence of embedded URLs and the link farm behavior point towards a phishing or redirection scheme, likely intended to deliver a secondary payload or lead users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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://ambrose.edu/sites/default/files/webform/fulakosilukubusovugatupus.pdf In PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/bedadijone.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/79062027218.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/subeditanutojodojewogize.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/49109440539.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/fabifuturofutip.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/70645978292.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/21691652676.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/dapajinosez.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/58234525485.pdfIn PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/4279473489.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/monufugabezexi.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/DOqCt-cVA4I/uplcv?utm_term=vicks+cool+mist+humidifier+filterPDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/31356988355.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/97035559296.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/5272012193.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/bidemuf.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/fazarixi.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_off0000e66a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE66A 5080 bytes
SHA-256: 286ec8e01c990a5296ca30b9658d9ddb49198dabd7af10322703796e2e236f8f
font_01_sfnt_off0000f791.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF791 11424 bytes
SHA-256: 331b5be78be80d3dae6d645f3625289962cb9f2366fed5a89e1e3b6cf36d1b13