Malicious PDF — malware analysis report

Static analysis result for SHA-256 9f363b2c77b8aa07…

MALICIOUS

PDF

70.5 KB Created: 2021-04-15 21:23:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 1ed70f91328305c90de856ec89d578ed SHA-1: 02daa5b87e3ea6e100f724f95ab07353ef318279 SHA-256: 9f363b2c77b8aa072e877927ce71772fee153abdcbd4ec25dea890c2e238b3a7
126 Risk Score

Malware Insights

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

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, with the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggesting these are used to create a link farm on disposable hosting. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics point towards a phishing or malware distribution scheme, likely leveraging spearphishing attachments as the initial access vector.

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.dgs-interparts.be/sites/default/files/55949953827.pdf In PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/xofarazenufokedakuzos.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/72789215659.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/danodajanenalidadalibebav.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/3563422068.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/80098342864.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/xubapubawaral.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/29410319198.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/bugoxugokerudanetisene.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/pifudolaloxafedotodela.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/xexazud.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/ratasivovo.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/LPIa9PGmDLg/uplcv?utm_term=midi+to+cv+gatePDF link annotation
    • https://community.princeton.edu/system/files/webform/26098210740.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/9071701793.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_off0000d7e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7E9 4864 bytes
SHA-256: b1e5752c72425935287b9efa9036b3577c2d7798cb96263f5202bf778af5dcf5
font_01_sfnt_off0000e8a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8A1 10740 bytes
SHA-256: d100ad2bf9e564cb1df78d849ade0b663af05df8f6ed725450bd67a85c64d71b