Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb0df05d3160d559…

MALICIOUS

PDF

75.8 KB Created: 2021-09-12 20:12:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 2becd1dad104dbbe1206a47a85c5b5c1 SHA-1: 9fbe31345f7ef5ef18f12345262a69e69eeb4e30 SHA-256: cb0df05d3160d55975ba65e75b4f186fdf7aa020f0abcc7d595943af9621aebb
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which are hosted on disposable domains or compromised WordPress sites, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest a phishing or malware distribution intent. The document body is heavily obfuscated and unreadable, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://krisoc.ru/uplcv?utm_term=tekken+3+ppsspp+iso PDF link annotation
    • https://8cj2aja7-8mxb.com/contents/files/vuwodosadubimiredafata.pdfIn PDF document text
    • https://pilot-nav.com/ckfinder/userfiles/files/79509645774.pdfIn PDF document text
    • https://debcopharma.com/userfiles/file/dajezotudasupopuxezase.pdfIn PDF document text
    • https://koratspring.com/upload/file/46447111425.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b71e2eca43---nolumalarusowakuj.pdfIn PDF document text
    • https://resortweeks.pro/userfiles/file/80199794079.pdfIn PDF document text
    • http://bangdinhphucat.com/quangbasanpham/app/webroot/upload/image/files/63532655072.pdfIn PDF document text
    • https://www.smartfutureexpo.com/ckfinder/userfiles/files/gevorukosoxawabemiwa.pdfIn PDF document text
    • https://booknowrentalimo.ch/userfiles/files/73723633988.pdfIn PDF document text
    • http://windmill-bv.com/userfiles/files/51230816501.pdfIn PDF document text
    • http://aerotechgroup.ru/img/outer/files/46569929671.pdfIn PDF document text
    • http://machinegroup.ru/img/outer/files/vewedusisosovulij.pdfIn PDF document text
    • https://censcakmu.org/board/file/files/rinajukedide.pdfIn PDF document text
    • http://kfnmsz.com/upfolder/e/files/20210912022247.pdfIn PDF document text
    • http://kunjipsc.com/uploads/files/fojixab.pdfIn PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/dd2300a5177367cffdb3851ad0011e43/812840106.pdfIn PDF document text
    • http://gopherandsquirrelcontrol.com/admin/images/file/9453030221.pdfIn PDF document text
    • http://humanitool.ru/userfiles/file/55150355865.pdfIn PDF document text
    • https://next-engineering.com/userfiles/files/dirige.pdfIn PDF document text
    • http://musiclivemarsala.com/userfiles/files/xamumab.pdfIn PDF document text
    • https://dalycity.com/wysiwygfiles/file/86003653392.pdfIn PDF document text
    • http://goldway.jp/upload/board/file/46536165994.pdfIn PDF document text
    • http://bestorkate.com/uploads/ckeditor/files/dizazapepuzazoxivik.pdfIn PDF document text
    • http://ulrike-mayer.de/userfiles/files/dasedogogunamejik.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613761bd37323---67174708321.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_off0000c1ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1EE 10064 bytes
SHA-256: f8e1244567041ef2283329315f4200389d3634a81d0795ff6efb9a2435a97bdf
font_01_sfnt_off0000d888.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD888 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f09a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF09A 18940 bytes
SHA-256: ac9c9fb4244c2397e861b666dd9bf8c269b30b0ad93ed57337946534a637247e