Malicious PDF — malware analysis report

Static analysis result for SHA-256 4de25d6dbf471c67…

MALICIOUS

PDF

83.5 KB Created: 2021-09-15 03:25:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 8773068dc28f4ad7b98f827d0657f0c6 SHA-1: a6a83ef8c5ae7347c0d2b951811055a78d62a22f SHA-256: 4de25d6dbf471c67db90f31fa96c60df3febe9932c729ae4fa247c481fe81e44
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. The file contains numerous embedded URLs, many pointing to compromised websites or disposable domains, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking clear user-facing content but containing numerous links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://cructi.ru/uplcv?utm_term=cinema+keren+21+online PDF link annotation
    • http://opersan.com/file/80459512831.pdfIn PDF document text
    • http://studioriboldi.eu/userfiles/files/toxasabakekupirujaraxuf.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/8b07d4c5dd1303506be0e76e6eb646ff/12323348520.pdfIn PDF document text
    • http://bannermaul.com/userData/board/file/48227642170.pdfIn PDF document text
    • http://patanamachine.com/imgUpload/files/71562058829.pdfIn PDF document text
    • https://joebalogh.ro/imagini_ws/28540275252.pdfIn PDF document text
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/161413928ccf61---58356916477.pdfIn PDF document text
    • https://nestsearch.in/admin/uploads/file/76630243076.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16136c08435f19---24755148657.pdfIn PDF document text
    • https://www.asoriofrio.org/ckfinder/userfiles/files/69438542415.pdfIn PDF document text
    • http://alothongtin.com/upload/FCK/file/puvowewolugifaxuvod.pdfIn PDF document text
    • https://sfeerweter.nl/userfiles/files/67979083350.pdfIn PDF document text
    • https://bluetact.com/locktactyuma/userfiles/file/12844231856.pdfIn PDF document text
    • http://kleinschaden.expert/userfiles/file/11219800922.pdfIn PDF document text
    • http://sportsgarten.com/editorData/file/vipapinebonejosipegat.pdfIn PDF document text
    • http://makassitools.com/userfiles/file///7719581548.pdfIn PDF document text
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/123b9c89bceb8bf84725a31843f6d57b/vudasiwaz.pdfIn PDF document text
    • http://www.cafeinca.com/img/public/contenido/file/dolasizuwinibigeju.pdfIn PDF document text
    • https://moyaexpresss.com/ckfinder/userfiles/files/begigoxajowadutubuvis.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/podalotari.pdfIn PDF document text
    • http://cdio.vn/uploads/userfiles/file/jopudezosarirupil.pdfIn PDF document text
    • http://ykzn8.com/upfiles/editor/files/newadeb.pdfIn PDF document text
    • http://harckocsik.hu/userfiles/file/fofutazetatemifoju.pdfIn PDF document text
    • https://philly.drinkpoint.com/uploads/files/92456617174.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_off0000e276.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE276 18028 bytes
SHA-256: 8ccfcff4db5aa72a14bd2401330f3d024c47ddb2d2e52e757fb80061bd6d84c9
font_01_sfnt_off00011114.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11114 10300 bytes
SHA-256: aa1b654329959a6ae8ba82250b43da7c477b6e8c00137724fe0cdc0dff7872b9
font_02_sfnt_off00012848.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12848 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1