Malicious PDF — malware analysis report

Static analysis result for SHA-256 2505dc0865fe5fe7…

MALICIOUS

PDF

79.4 KB Created: 2021-09-13 10:51:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6f8107dd12d1590adda66079631ed5b8 SHA-1: ee931f7b64bfac3938a88806e6937c433a3dd5ba SHA-256: 2505dc0865fe5fe7aa2fb00db2e603816e38a6f39fd13deda75335cfabafc9f4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains embedded JavaScript and numerous external URIs, many of which are hosted on potentially compromised or disposable domains, indicating a link farm designed to redirect users. The presence of embedded JavaScript suggests an attempt to execute malicious code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://richardchong.com/userfiles/files/55910840961.pdf In PDF document text
    • https://pomacanthe-art.fr/imagebeforeafter/files/52086221441.pdfIn PDF document text
    • http://asfalon.com/__files/file/34695169985.pdfIn PDF document text
    • https://dm288.com/slicice/file/78863859107.pdfIn PDF document text
    • https://i-chat.tw/js/ckfinder/userfiles/files/79650359293.pdfIn PDF document text
    • http://steinemann-ag.ru/wetomamozikosudoxemu.pdfIn PDF document text
    • http://manilag.com/FileData/ckfinder/files/20210906_96C1CD04E37B78B8.pdfIn PDF document text
    • http://veterina-naslunci.cz/userfiles/file/parex.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fb3f9eced2---kagoxuko.pdfIn PDF document text
    • http://igs.compcierge-asia.com/ckfinder/userfiles/files/3698927465.pdfIn PDF document text
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/bd7npue9hf771m7og8m27uflor/zimoxixanuwij.pdfIn PDF document text
    • http://sportingclubalbinia.eu/userfiles/files/gufisurovuk.pdfIn PDF document text
    • http://merwepizza.com/upload/file/83761482223.pdfIn PDF document text
    • http://novosib-sport.ru/ckfinder/userfiles/files/nemoxunolof.pdfIn PDF document text
    • http://minhphucvietnam.com/uploads/userfiles/file/visida.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/1613716e24f1a0---57524052967.pdfIn PDF document text
    • http://myepres.com/HotelEstimator/userfiles/file/91005146079.pdfIn PDF document text
    • https://prcomponents.com/ckfinder/userfiles/files/99000756348.pdfIn PDF document text
    • https://aordonez.com/images/contenidos/files/7944258736.pdfIn PDF document text
    • https://stradatextiles.com/upload/ckfinder/files/mikegumoj.pdfIn PDF document text
    • https://okazionche.com/files/5824932439.pdfIn PDF document text
    • http://denetimmusavirlik.com/userfiles/file/29560583593.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613bc83a2c397---54073746340.pdfIn PDF document text
    • http://bndweb.nl/upload/files/43003465667.pdfIn PDF document text
    • https://songhong-thudo.com/img/files/33433270069.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=vpn+permission+androidPDF 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d6f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6F6 16024 bytes
SHA-256: 18d633c8a829315a8d6df3646fe02a509692d4b1ce19df6404d44963be189edb
font_01_sfnt_off0001006f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1006F 10376 bytes
SHA-256: 191d15d954a5533931ae06cd1f1b9ad77e669c46734adcb40dc08ecfe47ffbd5
font_02_sfnt_off000117de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117DE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1