Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb4ff520fdae0b7c…

MALICIOUS

PDF

106.9 KB Created: 2021-08-24 19:08:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a2e6569f3b8642d1d5af08251ba44d51 SHA-1: 2630e0c6a2af3d8113b7624ca3d1ff5cc5d62534 SHA-256: cb4ff520fdae0b7c63d12d1fb081e06b550cd9bed15a56143be759cb5f8bcca3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites and are structured as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://aimara-bg.com/userfiles/file/4009920385.pdf In PDF document text
    • http://botosani.ro/img/uploads/file/sagetajusegakag.pdfIn PDF document text
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/019f10aa2684dd4653c880f3eb21c44b/talujogamunavoraziluzava.pdfIn PDF document text
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/87jqdu0nh3qcle18i91mn67bfr/11102768434.pdfIn PDF document text
    • https://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/bf8079134da83bb7f2194ad503fc3140/90345234912.pdfIn PDF document text
    • https://gites-les-bardots.com/userfiles/file/vidivexufogudutu.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/vk8jlea4oavq6b52jjnbd00pl3/katazakupobadane.pdfIn PDF document text
    • http://austintownfitch1980.com/clients/879833/File/95235468343.pdfIn PDF document text
    • https://airbays.com/userfiles/file/birubepamezugenaboku.pdfIn PDF document text
    • http://i-daa-wl.de/userfiles/79804513838.pdfIn PDF document text
    • https://casabresciani.it/uploads/file/83907882155.pdfIn PDF document text
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/h1rc2eervt3r65l3q70pg8op58/votexotunabufobirekexu.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/160a5a7dfdae43---1853593075.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7ca19783dc---41217887751.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/00ef5ebf5b3e56ba5aa7901cce0b549a/29273760741.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/8a99ec0859640fc37de8524a5205b86c/88366173305.pdfIn PDF document text
    • http://zonwering-belgie.eu/ckfinder/userfiles/files/wejelosemar.pdfIn PDF document text
    • https://mauspro.net/upload/files/gadubafijukemametixutu.pdfIn PDF document text
    • http://munnarinfo.in/userfiles/file/76414158259.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c30e3e37b64---debodatalerukuzipebuzaw.pdfIn PDF document text
    • http://exmar.it/foto_fck/file/90996497408.pdfIn PDF document text
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/b74a877356dc7b39b4e2834449d408ce/20157740068.pdfIn PDF document text
    • http://sl-light.ru/design/img/upload/file/pugejejuz.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf61216a2a2---tefuketedaweparere.pdfIn PDF document text
    • http://altinay-law.com/images/file/nexazupalanubola.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=antwone+fisher+pickett+familyPDF 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_off00013d05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D05 17464 bytes
SHA-256: 8a988a9a3834087ffc35396785c23ba6744300b1d2014e1e1fe3f9aa0712a70b
font_01_sfnt_off00016a9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16A9C 11020 bytes
SHA-256: c194ecec8c95d7b9802d695d6e087e5321dd0b4da2a66f3edb67d8d342f16786
font_02_sfnt_off00018433.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18433 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1