Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a1c98827e725b85…

MALICIOUS

PDF

80.2 KB Created: 2021-09-14 06:41:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: f9b7c2a30e0230b7f12e4d3000250e8e SHA-1: f07c577c7e076efdba819b7bddacdd802254a093 SHA-256: 8a1c98827e725b85ca96f42a4ad8e084d2942c3276446e4dfedff6fe59655a97
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. It also features a link farm pointing to multiple external URLs, some hosted on compromised WordPress sites, which are likely used to redirect users to phishing or malware download pages. The ClamAV detection and ML classifier strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://bkht.vn/userfiles/file/35226100993.pdf In PDF document text
    • https://pacantioquia.org/aym_image/files/45588635698.pdfIn PDF document text
    • http://internet-trade.eu/UserFiles/file/1648907690.pdfIn PDF document text
    • http://net-work.cz/data/file/giwarixewitadabavinukipak.pdfIn PDF document text
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613076c182400---57649557790.pdfIn PDF document text
    • https://pataniforum.com/admin/jquery/ckfinder/userfiles/files/jikomudapet.pdfIn PDF document text
    • http://thecuriosityshot.com/35320116966.pdfIn PDF document text
    • http://docando.es/js/ckfinder/userfiles/files/46278862243.pdfIn PDF document text
    • https://damiel.eu/userfiles/file/radutu.pdfIn PDF document text
    • http://ultraljud.nu/bild/files/22847756354.pdfIn PDF document text
    • http://bearings-home.com/userfiles/file/4194756422.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/ddd9ae8aed021139e50d2ffaf5dcb912/62793456053.pdfIn PDF document text
    • http://delfosventures.eu/userfiles/files/60126744280.pdfIn PDF document text
    • https://rdw-wolf.de/backend/ckfinder/userfiles/files/27621687175.pdfIn PDF document text
    • http://fitviewer.com/files/file/20980045298.pdfIn PDF document text
    • https://slotpt2.com/contents/files/zivilefukagekaxewek.pdfIn PDF document text
    • https://aprilboya.com/userfiles/file/nulawedojosunepezurox.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613be7b60df5a---rejoselisorus.pdfIn PDF document text
    • http://toflight.mobi/attachment/ckeditor/files/91c7a25e96e2201d8b4a5b7a001c47a2.pdfIn PDF document text
    • http://jamalcar.com/userfiles/file/6272568868.pdfIn PDF document text
    • http://inter-travel.hu/_user/file/wutirekadawiwunonozuxow.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=how+to+hack+into+your+old+snapchatPDF 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_off0000d309.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD309 18008 bytes
SHA-256: 0974ebdefda48419e1129f60c175cdf4c056134f1d9b1cbbebf415946ef4cd4b
font_01_sfnt_off000100af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100AF 10860 bytes
SHA-256: 5052504d9348e2ffc64b1a4744d258fe8b055e6aa1b32494c39981700194c20b
font_02_sfnt_off000119c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119C5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1