Malicious PDF — malware analysis report

Static analysis result for SHA-256 85dbf5cdac796d1e…

MALICIOUS

PDF

71.8 KB Created: 2021-09-21 23:59:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a1237efb2e090340fe03c1b2d62245e2 SHA-1: 67599150b6288dcb33eaef3ceede4f9d4fb7935f SHA-256: 85dbf5cdac796d1e5e7d8c0bcab16a055296ed6eec5f1f8b20595f67648778cd
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which point to disposable hosting, suggesting a link farm or redirection mechanism. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards it being used as a lure to external, potentially malicious, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://candybeauty.vn/upload/files/50250858116.pdf In PDF document text
    • http://www.motionmantra.com/userfiles/files/tazexumurupilixupopibaju.pdfIn PDF document text
    • http://sushibelovo.ru/files/vewotijakenepadebinilo.pdfIn PDF document text
    • https://altonika.pro/files/fck/file/49454168709.pdfIn PDF document text
    • http://bluecreator.biz/ckfinder/userfiles/files/gamuwunotiga.pdfIn PDF document text
    • http://engineersclasses4competition.com/files/others/33146457306.pdfIn PDF document text
    • http://mamitobe.ru/files/file/90987509871.pdfIn PDF document text
    • https://mma-montessori.com/admin/ckfinder/userfiles/files/kinoxinodanodamawudabug.pdfIn PDF document text
    • https://cuisinescartier.ca/upload/editor/file/20708751618.pdfIn PDF document text
    • http://coiffurenais.com/userfiles/file/9740925614.pdfIn PDF document text
    • https://bursakaynak.com/userfiles/file/88232478166.pdfIn PDF document text
    • http://easyreturn.store/userfiles/file/wadikavileroxopivorinu.pdfIn PDF document text
    • http://oasishs.com/uploads/files/20210907_162006.pdfIn PDF document text
    • http://blackhorsesc.pl/userfiles/file/26241540549.pdfIn PDF document text
    • http://theprojectmanagement.guru/cote_dor_import/admin/ckfinder/userfiles/files/ragelis.pdfIn PDF document text
    • http://transporteslaplata.com/imagenes_web/file/49471271701.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b22b553d05---mubofud.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cb65cec469---75435497052.pdfIn PDF document text
    • http://dansensvenner.dk/imagesfile///banusozenosofajevij.pdfIn PDF document text
    • http://sntaviator.ru/ckfinder/userfiles/files/12388183760.pdfIn PDF document text
    • https://ildiko-szepsegszalon.hu/userfiles/file/vezelipimibuwix.pdfIn PDF document text
    • http://keemunblacktea.cn/uploads/file/051604405151.pdfIn PDF document text
    • http://fine-trading-knotwork.com/uploads/media/kidiramenipajorefexilipi.pdfIn PDF document text
    • http://hdg-gmuend.de/userfiles/files/846425314.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=names+that+start+with+s+and+end+with+tPDF 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_off0000b731.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB731 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF43 16592 bytes
SHA-256: 1b086205ede43c85dcdf3c388ce066459fd96a0df3617797583db3e9519de046
font_02_sfnt_off0000fa02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA02 10412 bytes
SHA-256: 89bee257b9911c1ff131781d887ce8dedcefa578bc69d78dc91ed2c514f32158