Malicious PDF — malware analysis report

Static analysis result for SHA-256 23cb7b4904208dfd…

MALICIOUS

PDF

71.9 KB Created: 2021-09-23 01:04:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: ec196686a923145722f633c03c2f3a5d SHA-1: 989cc0ccd4043934b9f571041cc7808588dfdc7c SHA-256: 23cb7b4904208dfdf8e675b796840a7d53e71e33e931c322091969b261f989ea
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external links, many pointing to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 7

  • 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.
  • 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 https://hoangphatdanang.com/uploads/image/files/zapituvalatosigobixemite.pdf In PDF document text
    • http://skolky.info/foto/images/file/21622620113.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/d65727f619cfa38d26a7b2a3e2c5f6ce/17515839431.pdfIn PDF document text
    • http://noclegsosnowiec.pl/eurostyl/photos/file/rofigowusogafibapakexomo.pdfIn PDF document text
    • https://atasuorganiktarim.com/upload/ckfinder/files/wexamisimomofer.pdfIn PDF document text
    • http://alibabashipping.com/userfiles/file/xawovak.pdfIn PDF document text
    • https://karjerastests.bankai.lv/ckfinder/userfiles/files/5780431034.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16137dd7b3daa1---52585167957.pdfIn PDF document text
    • https://ooobelkom.ru/ckfinder/userfiles/files/83267382640.pdfIn PDF document text
    • https://sensormaticltd.com/app/templates/js/ckfinder/userfiles/files/81974029773.pdfIn PDF document text
    • http://hiniceshine.com/upload/kosijilezuj.pdfIn PDF document text
    • http://shceping.com/upFile/photos/2021-9/file/89633887644.pdfIn PDF document text
    • https://knoxvilleremembers.com/media/57018627118.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/fdfb3047c449698313100a435edcbe6c/24375575566.pdfIn PDF document text
    • http://blackivy.pl/userfiles/file/24291915977.pdfIn PDF document text
    • http://seamacros.com/upload/file/rijodomesetezepem.pdfIn PDF document text
    • https://purmoradiatoriai.lt/images/files/72960622023.pdfIn PDF document text
    • http://client.diffuse.info/files/xawolakoriladojazero.pdfIn PDF document text
    • http://bilafafafa.com/shopadmin/upload/files/76471802154.pdfIn PDF document text
    • http://webursitet.org/Files/file/varofefasivifo.pdfIn PDF document text
    • http://optikametuje.cz/userfiles/file/30793941143.pdfIn PDF document text
    • http://caogenzhiben.com/filespath/files/20210902122643.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=an+imperial+affliction+pdfPDF 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_off0000b73f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB73F 10596 bytes
SHA-256: 1d4d807142bf89dad3ec63fe9f81fb8750fcb82a6b44017bf25d745788304473
font_01_sfnt_off0000cf5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF5C 16680 bytes
SHA-256: 96b099576546fe486062abe61eb776c8f7a18671f3f46585247edf1fb43c8979
font_02_sfnt_off0000fa01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA01 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1