Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc5acf1a2736616c…

MALICIOUS

PDF

74.6 KB Created: 2021-04-12 20:10:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-17
MD5: 01713c90966402074efe42fd56365ba6 SHA-1: e77279c60ce85af2dff4de66ae05200ac66325ae SHA-256: dc5acf1a2736616c9d567bc26f0e88d9eecbd2c3f818f6d46f62dcb2d2393ff6
126 Risk Score

Malware Insights

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

The PDF document was flagged as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. The document contains numerous embedded URLs, many of which are hosted on seemingly legitimate domains but are part of a link farm designed to redirect users. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests a deliberate attempt to obscure the final destination through multiple redirects.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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 https://www.telluridescience.org/sites/default/files/tstc-applications/90077644064.pdf In PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/27880179426.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/46846662681.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/fulakosilukubusovugatupus.pdfIn PDF document text
    • https://europa-ts.ru/sites/default/files/webform/81905598419.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/vawutudujenopudup.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/25507329945.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/42406093886.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/lolavojirubopikumu.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/suvexaxobufakup.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/80098342864.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/~3/1KS0DP0cxss/uplcv?utm_term=disposiciones+legales+acerca+de+la+obligatoriedad+de+la+contabilidadPDF link annotation
    • https://drones.princeton.edu/system/files/webform/65601020807.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/85824103047.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/wetesagepe.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_off0000e332.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE332 5380 bytes
SHA-256: 08fc67586ba8aa7ac1a3f28d7b5c5a5cbb285ac1bec9ff4e3596e6767596ce67
font_01_sfnt_off0000f588.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF588 11528 bytes
SHA-256: a3036cd2f61619789433060ca91b5c37ae011d5b25e1d798ba2301a4befbbae7