Malicious PDF — malware analysis report

Static analysis result for SHA-256 81a6a5224af5bf5d…

MALICIOUS

PDF

81.0 KB Created: 2021-09-04 14:03:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 90a9f0865927d519ed6d07a30af07f0e SHA-1: c31836118b777a68d17a3f86ca18342d3bd3d7a6 SHA-256: 81a6a5224af5bf5d2d95c635a3f3d3fce2af9cf94f8fb46694a775872ca6fed9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the primary attack pattern involves luring users through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://huntic.ru/uplcv?utm_term=best+manual+cars+2019+uk PDF link annotation
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16096a94859245---58491912722.pdfIn PDF document text
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/9381f76fab8833b922d025ced0317bf0/divipidepugo.pdfIn PDF document text
    • https://lightspec.ca/wp-content/plugins/super-forms/uploads/php/files/47d89fce952a777494843b78957655b1/77352899165.pdfIn PDF document text
    • http://daiichigroup.net/uploads/news_file/13252811817.pdfIn PDF document text
    • http://iuoooo.com/filespath/files/20210810071143.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cbafcdf19b4---3585970617.pdfIn PDF document text
    • https://dbjadow.pl/attachments/file/kanowebaverogududo.pdfIn PDF document text
    • https://nestsearch.in/admin/uploads/file/zapokajabosukidebovaxasis.pdfIn PDF document text
    • https://telewebmarketing.com/FCKeditor/file/doburebinolifa.pdfIn PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/h3ggf29ent5s8i9877f3e1jnb8/71554205364.pdfIn PDF document text
    • http://firewheels.pe/userfiles/file/92063523401.pdfIn PDF document text
    • http://architettosirocco.it/userfiles/files/gadolitejoge.pdfIn PDF document text
    • http://muszempilla.com/files/file/49052970524.pdfIn PDF document text
    • http://dichvutheapec.com/upload/FCK/file/58156334084.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080746240357---gebozurofegabonokelikiwo.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/vanozedosamuguzabiter.pdfIn PDF document text
    • https://motoquadro.de/userfiles/file/lisavewon.pdfIn PDF document text
    • http://quranday.org/userfiles/file/gigovitukewol.pdfIn PDF document text
    • http://scales-center.com/shop/fck_file/file/zuvatogapiwomoxetefevaxuz.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/160987899e1d95---31072224753.pdfIn PDF document text
    • http://thanhlapcongtykiengiang.com/upload/ck/files/dejiwamowunamixip.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_off0000d6cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6CD 10888 bytes
SHA-256: 00413f316e2d89f5b250661ecc93b6bae8e53b99b0c3b791cbc276495bb2c0bb
font_01_sfnt_off0000f024.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF024 18080 bytes
SHA-256: 65697f65226435a4aad8e6bb965a28010e751eb7a9a60319f46909275070d687
font_02_sfnt_off00011ee8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EE8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1