Malicious PDF — malware analysis report

Static analysis result for SHA-256 41f4b334db528e3d…

MALICIOUS

PDF

81.2 KB Created: 2021-09-13 03:19:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: f923252280142a85e6257c2a264f36b8 SHA-1: de2c162b25cacbf3fda8154e0bfa0255d6957ad4 SHA-256: 41f4b334db528e3db2a507e9f7a94fd0f3ddd53e01092c9b0a0d6be3e93e6367
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of embedded URLs, many of which point to disposable hosting, indicating a link farm designed to redirect users to potentially harmful sites. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure and heuristic firings strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://chcial.ru/uplcv?utm_term=link+sd+card+to+internal+memory PDF link annotation
    • https://inverpalmas.com/aym_image/files/gabogijozeganatobijijusuw.pdfIn PDF document text
    • https://praktijkbinnenstad.nl/file/68655364566.pdfIn PDF document text
    • https://asigurareingermania.ro/wp-content/plugins/super-forms/uploads/php/files/6k05a7hmr0r6dd6hoco256r3h2/dinabi.pdfIn PDF document text
    • http://architettotoma.it/userfiles/files/sitiri.pdfIn PDF document text
    • http://chipublichouse.com/ckfinder/userfiles/files/24919319855.pdfIn PDF document text
    • http://cjpharmtech.com/upload/files/55319352421.pdfIn PDF document text
    • https://ketex.com/trcgp/ckfinder/userfiles/files/bowobezedigoj.pdfIn PDF document text
    • http://dxczx.com/ckfinder/userfiles/files/20210913_053229.pdfIn PDF document text
    • http://ustunongel.com/image/files/37608417361.pdfIn PDF document text
    • https://idosekotthonaveresegyhaz.hu/files/files/78425353996.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b50bebf787---63731922689.pdfIn PDF document text
    • http://energy-labels.com/userfiles/file/deduropapogovapegovulevib.pdfIn PDF document text
    • https://www.zolmedis.lt/ckfinder/userfiles/files/76892879316.pdfIn PDF document text
    • https://jasmijnbloemengroen.nl/userfiles/file/84800499757.pdfIn PDF document text
    • http://dogable.de/userfiles/file/sirigo.pdfIn PDF document text
    • http://artanuji.ge/admin/ckeditor/ckfinder/userfiles/files/wagokudopaxeregetaso.pdfIn PDF document text
    • https://buildingexpertsdirectory.com/ckfinder/userfiles/files/28074318792.pdfIn PDF document text
    • https://partnermind.cz/images/files/87557095956.pdfIn PDF document text
    • http://sun-eko.eu/files/file/rujutirapisojuzepitas.pdfIn PDF document text
    • http://rulada.by/upload/editor/files/ziguvonoxilu.pdfIn PDF document text
    • https://inprovitmexico.com/ckfinder/userfiles/files/gositurazozizo.pdfIn PDF document text
    • http://changrung.com/ckfinder/userfiles/files/muvoxoxapomit.pdfIn PDF document text
    • http://smarttechsolutionukltd.com/uploaded_files/userfiles/files/42125567327.pdfIn PDF document text
    • http://nexxstep.nl/userfiles/file/95018941027.pdfIn PDF document text
    • https://stiff.pl/ckfinder/userfiles/files/getez.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_off0000d79e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD79E 10692 bytes
SHA-256: f989f02a47bd206517fd4363435b95c520fab265ec35f004b99b8067c6be1a16
font_01_sfnt_off0000f02a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF02A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001083c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1083C 18604 bytes
SHA-256: 823cad6115d0fbd7c0ba9f7fab052e9371559b4837a6774abcfeaab9dc14d280