Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f05543f4cc708f0…

MALICIOUS

PDF

75.6 KB Created: 2021-09-16 11:10:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 3d76c010f63756272e15d3a83918815f SHA-1: d33a6ff91a100cd153d131de06b6d58de2faa398 SHA-256: 4f05543f4cc708f0c9b497002f9d26a1c7fa2c7e6f00e0965345f0fe694b70ec
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains embedded JavaScript and a high number of external URIs pointing to disposable domains, indicating a link farm designed to obscure the true destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The embedded JavaScript is likely used to facilitate the redirection to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • 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 http://bajcsidavidfoto.com/_user/file/wopojiwewizasizug.pdf In PDF document text
    • https://buildingexpertsdirectory.com/ckfinder/userfiles/files/fobevu.pdfIn PDF document text
    • http://weingut-suppan.at/files/23184019300.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee525da826---degubu.pdfIn PDF document text
    • https://zoldlaptop.hu/ckfinder/userfiles/files/gajore.pdfIn PDF document text
    • http://cmrivestimenti.com/userfiles/files/8896940710.pdfIn PDF document text
    • http://vip-cond.ru/userfiles/file/gukigijof.pdfIn PDF document text
    • https://wonwon.taipei/photo/file/55167426180.pdfIn PDF document text
    • https://www.caissedesecolesdu5eme.fr/backoffice/ckfinder/userfiles/files/53163472715.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/161364e928ca8d---jenafavizurojuji.pdfIn PDF document text
    • http://3e-recycling.ru/app/webroot/filesfiles/29978909686.pdfIn PDF document text
    • https://pieseautocomenzi.ro/userfiles/file/82065774511.pdfIn PDF document text
    • http://collegium-connect.nl/ckupload/files/powugetak.pdfIn PDF document text
    • http://shiokuda1.com/contents/files/94083433843.pdfIn PDF document text
    • http://pphu-joanna.pl/fckpliki/file/25692333565.pdfIn PDF document text
    • http://fotocaroli.it/userfiles/files/14748749458.pdfIn PDF document text
    • http://taketty.xyz/js/ckfinder/userfiles/files/9108078838.pdfIn PDF document text
    • https://kltccompany.com/ckfinder/userfiles/files/dafabasota.pdfIn PDF document text
    • https://arhstroi.by/uploads/files/13222141250.pdfIn PDF document text
    • http://sushinamu.com/uploads/files/90159150338.pdfIn PDF document text
    • http://stilna-ya.com/_userfiles/file/xobiboja.pdfIn PDF document text
    • http://otvorene-srdce.sk/userfiles/file/74695238543.pdfIn PDF document text
    • http://gamaxmotor.cz/data/dokumenty/todotejeguj.pdfIn PDF document text
    • https://perfumes.dropship-tracking.com/userfiles/files/vawixojudelojaxogapom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=how+to+install+haxm+in+android+studioPDF 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_off0000c506.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC506 10660 bytes
SHA-256: 30677e415a6aa68a88f658ec8394ad615260809012ce62d03acd06f9264d4f29
font_01_sfnt_off0000dd39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD39 16640 bytes
SHA-256: 321bdd08d31d5da1f27117918f38dd6b1558f5fbe91e55e2d63d7fe3241fc36a
font_02_sfnt_off00010845.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10845 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1