Malicious PDF — malware analysis report

Static analysis result for SHA-256 a263ffc81433b52b…

MALICIOUS

PDF

88.8 KB Created: 2021-06-18 12:00:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: 5c407d23efe17a7534e88d65a8c36777 SHA-1: c207a87d9b0e53d889bca77fe5bf7f62fbbbaeba SHA-256: a263ffc81433b52b09542eb783ca1ecd0120220c0505e52bfd626658b0f7b317
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress sites and other disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 http://asesorgubernamental.com/images/file/wesovosowobepi.pdf In PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/160819c3730240---dimazujomezogex.pdfIn PDF document text
    • http://progfin.pl/userfiles/file/kelebikumebasujet.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160b5834af2169---81607963070.pdfIn PDF document text
    • https://investainternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2c947e0b41---22935899487.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e483ad7bbb---78662674265.pdfIn PDF document text
    • http://bochosushi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b9127125ba---75832667036.pdfIn PDF document text
    • http://www.jamesbgriffinlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092d9cd4dd1f---90691276721.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/db638a0a03c980b3681c5d17a9f32781/53292564283.pdfIn PDF document text
    • https://pjkconstruction.ca/images/file/jonekelo.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609747b5a198e---53231279559.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a5374e7712---36096499208.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/160984ac2b6f5e---vujorega.pdfIn PDF document text
    • http://english-life.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607211a8b51ad---mimage.pdfIn PDF document text
    • http://shethof.ch/cgi-bin/dynamisch/file/vudutatiwujalotatopinatu.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/YTWXjIUwRh0/uplcv?utm_term=wii+theme+song+violaPDF link annotation
    • 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_off00011c3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C3F 5076 bytes
SHA-256: 988e4eb9c84070fa0fa75ec07d2d69836d315e8f59293ce4c626e6b0861fb33f
font_01_sfnt_off00012d71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D71 12428 bytes
SHA-256: c99923df9f3205dd0a03de084a2b46e97959cbada1a5a5c30b5eb2c8f6cd4c62