Malicious PDF — malware analysis report

Static analysis result for SHA-256 eb5a8a9fcb0d4d17…

MALICIOUS

PDF

81.1 KB Created: 2021-09-09 16:18:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 164f2abbb7edbfd075dfb12a5cfd23b0 SHA-1: 9bfbfbd491ce5fe2a0a3879cc730fe0a3f772522 SHA-256: eb5a8a9fcb0d4d17b9c462aea11399aa5222bc059a4d20affae95119f34cfb28
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, indicating it is designed to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests a link farm strategy, likely for SEO poisoning or phishing. The ML classifier and ClamAV detection further confirm its malicious nature, with the embedded JavaScript likely serving to facilitate the redirection or exploit.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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
  • 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://studiocastigli.eu/userfiles/files/dovetixomijomuzafalu.pdf In PDF document text
    • https://kamhosting.nl/ckfinder/userfiles/files/53051918565.pdfIn PDF document text
    • http://belgium-ex.com/images/blog/file/fogaxezasisemilitufa.pdfIn PDF document text
    • http://gzcaifeilai.com/ckfinder/userfiles/files/202109012123072647.pdfIn PDF document text
    • https://harteron.ee/userfiles/file/65400682320.pdfIn PDF document text
    • http://escuelasfutbol8.com/docs/files/86594625412.pdfIn PDF document text
    • https://dubigroup.com/admin/fckeditor/editor/filemanager/connectors/upload/file/zevenipitagitisaxiwupap.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131643e5be5a.pdfIn PDF document text
    • https://a-metal.e-giant.net/archive/file/files/32300878950.pdfIn PDF document text
    • https://minervatech.work/js/ckfinder/userfiles/files/87342439758.pdfIn PDF document text
    • http://kesherisrael.com/uploadEditor/files/novipofek.pdfIn PDF document text
    • http://murasakijr.com/uploads/files/rasisitidalibolonux.pdfIn PDF document text
    • https://kingyao.com/uploadfiles/files/20210907_073207_4549.pdfIn PDF document text
    • https://lp-tracking.com/userfiles/file/volegadomax.pdfIn PDF document text
    • http://carszana.com/image/upload/File/45135123489.pdfIn PDF document text
    • http://longvu.vn/Images_upload/files/fatenemafiwemo.pdfIn PDF document text
    • http://foto-klub.dk/userfiles/file/21059328631.pdfIn PDF document text
    • https://kaptenhoki.com/contents/files/tegilev.pdfIn PDF document text
    • http://1544-7419.net/upload/fckeditor/file/34854574816.pdfIn PDF document text
    • http://mikol-styl.cz/userfiles/file/vibasimibelo.pdfIn PDF document text
    • http://ghibms.com/userfiles/files/64909035665.pdfIn PDF document text
    • http://tischlerei-schlusche.de/sites/default/files/file/70636061640.pdfIn PDF document text
    • https://rainbowfurnitures.com/files/files/sipezivajo.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161309465ddaaa---pubotelotazi.pdfIn PDF document text
    • https://dalycity.com/wysiwygfiles/file/17994367110.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=words+with+o+sound+phonicsPDF 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_off0000d8e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8E6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f0f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0F8 17820 bytes
SHA-256: cc67dfca50f6ce291c66aa60c98e482eb3c6e339ffade2947731e7afe97c70d5
font_02_sfnt_off00011f1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F1A 10448 bytes
SHA-256: f5873b57dcca3aaf07ade9792aad022ac09aafd9bd81cd63acd5663ce8527270