Malicious PDF — malware analysis report

Static analysis result for SHA-256 9b78b8a671fad1f7…

MALICIOUS

PDF

71.4 KB Created: 2021-04-20 09:20:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 2af3a801365ae49b122ce47332f93809 SHA-1: 4c8fb424d0793363a4327b0c5883f8de9fc62c99 SHA-256: 9b78b8a671fad1f78d92a685997f61975d09ae887a516bb3daa9423f241775a8
126 Risk Score

Malware Insights

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

The PDF document contains obfuscated text and multiple embedded URLs, with one heuristic specifically identifying it as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were directly extracted, the PDF structure and embedded links suggest an attempt to redirect the user to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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/41094691834.pdf In PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/zavemazawutojene.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/koxajupenukolipidawikopi.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/65000750087.pdfIn PDF document text
    • https://www.newburghgroup.com/sites/default/files/webform/resumes/falaburisidibiwad.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/86303695333.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/welukugipevodabarovefeweb.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/woluweweketasuzizolog.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/96040264728.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/86947183128.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=what+is+the+most+watched+sport+in+canadaPDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/21250884575.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/ninavixokamorul.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cda6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDA6 5172 bytes
SHA-256: b52bc0ed1edfcfad7ede5e372254db4c126b3ffb2905298cc1ba778ecf85552f
font_01_sfnt_off0000df26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF26 10320 bytes
SHA-256: 6f9b2f952a5cf073f93d7170f27dffe4efdb9248e9bfa72a58e333670269cf81
font_02_sfnt_off00010238.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10238 4324 bytes
SHA-256: 1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e