Malicious PDF — malware analysis report

Static analysis result for SHA-256 a55634a7c4b4efd4…

MALICIOUS

PDF

73.3 KB Created: 2021-09-17 11:17:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 7c8d4fdfd3befe8d55dcc15daa850285 SHA-1: 03c52e80a4b7e8ef56f0e8ad0056b42816785876 SHA-256: a55634a7c4b4efd4bb82841a06c355b102710ecb0c8b78df573111d3f82d6e06
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are part of a link farm hosted on disposable domains, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a malicious document designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://nomylo.ru/uplcv?utm_term=oxygen+os+for+note+5+pro PDF link annotation
    • https://twinscooking.nl/twins/userfiles/file/dotuf.pdfIn PDF document text
    • http://expertcomptablecourreges.fr/michel_courreges/userfiles/file/resisesanez.pdfIn PDF document text
    • http://khodahoanglang.com/admin/webroot/upload/image/files/19374476210.pdfIn PDF document text
    • http://tmtechvn.com/webroot/img/files/welazijaxakakolekujid.pdfIn PDF document text
    • http://rozynoklinika.lt/userfiles/file/84078164055.pdfIn PDF document text
    • https://tahitotfalu.hu/ckfinder/userfiles/files/jikekekuriwima.pdfIn PDF document text
    • https://efnnma.org/files/file/38804526866.pdfIn PDF document text
    • https://telliogluhukuk.com/userfiles/file/66480104051.pdfIn PDF document text
    • http://e5tbr.alruaa.com/ckeditor-ckfinder-integration/uploads/files/sazudisemuzupevetefa.pdfIn PDF document text
    • https://netpage.info/userfiles/file/34964982021.pdfIn PDF document text
    • http://lachina.cn/upload/file/fanususitizufanisuvugu.pdfIn PDF document text
    • https://kaisar168.com/contents/files/74477276028.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/16139ffaf22608---lezoje.pdfIn PDF document text
    • https://grdr.org/paidel/ckfinder/userfiles/files/ziboti.pdfIn PDF document text
    • https://euroquimicadistribucion.com/zabaleta/data/imagenes_contenidos/file/43666464258.pdfIn PDF document text
    • https://impulsa.mantareys.net/uploads/plantillas/files/25118098521.pdfIn PDF document text
    • https://metnar.pl/web/uploads/files/19650201909.pdfIn PDF document text
    • http://zoo-foto.cz/userfiles/file/wobofuxawozenaneduvetav.pdfIn PDF document text
    • https://rodolphe-blanchet.fr/Rodolphe/fckeditor/file/12026877775.pdfIn PDF document text
    • http://muntepa.com/userfiles/files/8194261532.pdfIn PDF document text
    • http://studioingtassinari.eu/userfiles/files/fivapabaruwobavuki.pdfIn PDF document text
    • http://barahi.com/assets/userfiles/files/fuvakuwotegapakenepokuz.pdfIn PDF document text
    • https://saikekanglun.com/filespath/files/20210917134839.pdfIn PDF document text
    • http://rooptex.com/uploads/37300049071.pdfIn PDF document text
    • http://kimsanghun.com/upload/userfiles/file/202191263382877.pdfIn PDF document text
    • http://ac-kenigsberg.ru/files/file/10464384029.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://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_off0000bcd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCD2 16284 bytes
SHA-256: 61f3be139b5b733a7b0d1965e5fdbfba0f011128dd22da108503dd91d584c899
font_01_sfnt_off0000e71c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE71C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ff33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF33 10608 bytes
SHA-256: c8d14bbc8bfc2e398e9acfa0cad439c84111241e6ffbbe0afe9e3d8a3b99fb5e