Malicious PDF — malware analysis report

Static analysis result for SHA-256 35a8cfb69e4fbc01…

MALICIOUS

PDF

64.4 KB Created: 2021-06-24 07:55:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 96d50c98e9715e4e4a5f4831cb35d8a4 SHA-1: 0c1b81b3acce03d374cb2f8fd2af8d7f4423ba19 SHA-256: 35a8cfb69e4fbc0114f46d695f0c1856a0208d57be6386583ec93ec93371bb4e
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF contains numerous embedded URLs pointing to compromised WordPress uploads and other disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple external URI heuristics supports a high confidence assessment. While no scripts were directly extracted, the structure suggests it's intended to lure users to external sites, potentially for further exploitation or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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 https://laborke.ru/uplcv?utm_term=telugu+background+music+ringtone PDF link annotation
    • https://tycoonmarine.com/userfiles/files/79916523254.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1609eadd78dcda---50444543975.pdfIn PDF document text
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/160987e815ebed---7386198908.pdfIn PDF document text
    • http://toonesk.com/upload/femuzajatoxamukozalod.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/kadosagiwufanudurik.pdfIn PDF document text
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a419f92f58d---mezujadanopijufun.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b37c4d4fd02---68740240509.pdfIn PDF document text
    • https://yourtuscanyguide.com/wp-content/plugins/super-forms/uploads/php/files/umurblqebnns5a2d6golct7fi3/22007385455.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/54979a5526f27850a93b175171e645b9/nagoj.pdfIn PDF document text
    • https://www.infrascale.com/wp-content/plugins/super-forms/uploads/php/files/c2e699ec4a57d15b6017959d817d41f9/jotabanawidekagowaxupug.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5d023692a6---47953459113.pdfIn PDF document text
    • https://onhimalayas.com/ckfinder/userfiles/files/wiwafavamupetoku.pdfIn PDF document text
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/22bf91ee8f1caa0d536655b96be28fc8/vuxonetosobunibidu.pdfIn PDF document text
    • https://sailstudy.in/ckfinder/userfiles/files/93687886066.pdfIn PDF document text
    • https://www.electriclighting.com/wp-content/plugins/super-forms/uploads/php/files/ec16178d7ccf3b0d1d11db27977382ce/73418196533.pdfIn PDF document text
    • https://betalinktech.com/blmedia/file/jemakeguzagasiwe.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off0000bd10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD10 5412 bytes
SHA-256: dd5b0efe4b192651a2209a4e730d15834f2ffd4a992bd121050116fa977fef24
font_01_sfnt_off0000cf64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF64 10444 bytes
SHA-256: af650a3de1ee64cabb27a964b4694e97a433fae4aca4a7824a0ef8605ccb6342