Malicious PDF — malware analysis report

Static analysis result for SHA-256 c37de0aeaca403eb…

MALICIOUS

PDF

82.9 KB Created: 2021-09-16 23:58:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 36cb0cd6f051d7a95c14ff4e6a91ef9f SHA-1: 4baa515c69a92da7b3d3d9733ac59082febc2051 SHA-256: c37de0aeaca403ebb4043ea8fb48ff7b8ab82ae16cfd54c658dbac95c6597022
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it functions as a link farm. The PDF contains numerous external URLs, many pointing to compromised CMS uploads or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of 'utm_term' parameters in some URLs further supports the idea of tracking user interactions for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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=bolna+song+download+mp4 PDF link annotation
    • https://hagakure.by/upload/editor/files/ligetaredenixem.pdfIn PDF document text
    • https://atpl.aero/ckfinder/userfiles/files/67357940072.pdfIn PDF document text
    • http://abwingsva.com/uploads/files/gisap.pdfIn PDF document text
    • http://xn----ctbguteehkho5h.xn--p1ai/ckfinder/userfiles/files/31436173000.pdfIn PDF document text
    • https://www.playitdirect.ca/ckfinder/uploadfiles/files/16576187691.pdfIn PDF document text
    • http://om-ar.com/userfiles/file/69742929453.pdfIn PDF document text
    • http://vitrine-prof.com/files/24451280498.pdfIn PDF document text
    • https://marwaautorepair.com/nbloom/fckuploads/file/65031843417.pdfIn PDF document text
    • https://vleek.com/uploads/files/fozidujavusovug.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613de168a1317---58825250726.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b5ed337ca3---nimevisopalujepubewi.pdfIn PDF document text
    • http://receptlap.hu/files/26529912779.pdfIn PDF document text
    • https://abhimaninteriors.com/ckfinder/userfiles/files/matoturo.pdfIn PDF document text
    • https://partnermind.cz/images/files/ramogolofomefinenapuxoxed.pdfIn PDF document text
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/pbuldjfsqd3hc1j0aqjkgbj977/gigadolaferukuze.pdfIn PDF document text
    • http://www.s-prom.si/fileupload/file/tirezije.pdfIn PDF document text
    • http://massintech.ru/img/outer/files/zonavotusudimitujebigus.pdfIn PDF document text
    • http://ncdesign.it/userfiles/files/kokeketazux.pdfIn PDF document text
    • http://eminenceinc.com/userfiles/file/tifivogudusasowanovakak.pdfIn PDF document text
    • http://kvrhousing.com/uploads/kujakigominepowov.pdfIn PDF document text
    • https://nutricount.cz/UserFiles/File/wotejoxabir.pdfIn PDF document text
    • https://gdaniec.com/upload/files/novumawuxi.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_off0000dee9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEE9 10532 bytes
SHA-256: ff30602a1d5d77c8962293b7b7f08d7553915b31a50581229540eeef7e9ad29c
font_01_sfnt_off0000f6c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6C4 18060 bytes
SHA-256: 5acfb0faac695ca6019cbe012a38acd835f32020cb324c84b4f1cc6c456a1b08
font_02_sfnt_off000125fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1