Malicious PDF — malware analysis report

Static analysis result for SHA-256 51c939056b6f3298…

MALICIOUS

PDF

69.5 KB Created: 2021-04-09 19:54:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: a07158e856b1d9a2772575404f7c22ae SHA-1: 76047b8f9b67729c4a0c8a97fa4fe827e8dc3ccd SHA-256: 51c939056b6f32987a2f07fe92ed9e0b9bdd558e9458204c91682f42394113c8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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.natsihwa.org.au/sites/default/files/webform/81826716543.pdf In PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/lomaxitafuvutatu.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/mimixinaxeralowevowijut.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/bukitonixoravutewoluba.pdfIn PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/dojoxopanikofogenag.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/19824170549.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/30199048500.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/natogaj.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/xubapubawaral.pdfIn PDF document text
    • https://www.woonsocketri.org/system/temporary/webform/viwubamonutimujogigifowi.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/71926652616.pdfIn PDF document text
    • http://www.birdlifebotswana.org.bw/sites/default/files/webform/sightings-sketches/bikepekeroluxujopabiko.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/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=how+big+is+the+note+5PDF link annotation
    • https://community.princeton.edu/system/files/webform/64301273598.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_off0000d57a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD57A 4928 bytes
SHA-256: 911d4b5976c6ed17507c8ee3cc97dee7ebd63ab5f1c56286b48f1bca864dd5cb
font_01_sfnt_off0000e65e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE65E 10344 bytes
SHA-256: deae14b35062d654eb627aafb9077c5e4e1db51c951724113575c03176928786