Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc237c3b6cba4027…

MALICIOUS

PDF

91.7 KB Created: 2021-08-11 15:28:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-02
MD5: 4add5ec7c120208333b694d17ea2b6a5 SHA-1: 64d2e7e796bd0bf0a79c5e80c14bd4ad03040532 SHA-256: dc237c3b6cba402750cf07f305a2147d91c28501a19d2efc826f488b566f1d74
172 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories, presents a deceptive download button and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 8

  • 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.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b633b75dee4---19194470442.pdf In PDF document text
    • https://foundryindia.org/userfiles/file/73903419589.pdfIn PDF document text
    • http://caythuocdangian.net/images/files/vudevazufixefopopi.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/c1778c9f5634ed9a0c21efaf9376b860/totitodesupowav.pdfIn PDF document text
    • https://mgc.to/sites//web/upload/files/60749076420.pdfIn PDF document text
    • http://furniture83.com/upload/files/lavaxizelepunet.pdfIn PDF document text
    • http://perlawarmii.pl/userfiles/file/86832947897.pdfIn PDF document text
    • https://cecprint.com/images/file/98487453720.pdfIn PDF document text
    • http://alnadaoil.com/userfiles/file/bekerobazuzodek.pdfIn PDF document text
    • http://07-3739589.com/CKEdit/upload/files/kovavusawakubanufe.pdfIn PDF document text
    • http://mulroyenvironmental.ie/userfiles/file/43495973461.pdfIn PDF document text
    • https://costabravas.com/uploads/localidades/files/44469571485.pdfIn PDF document text
    • http://labmansour.com/app/webroot/js/ckfinder/userfiles/files/80025760873.pdfIn PDF document text
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/rh1uq74dugg9r90khbvisu4qh6/zezimenodupe.pdfIn PDF document text
    • http://daedukgs.com/admin/fckeditor/data/file/20210710172345.pdfIn PDF document text
    • http://shukokai-voves.fr/userfiles/file/gomuxatudozepefarataweka.pdfIn PDF document text
    • http://sanmorales.es/userfiles/files/gabuwiren.pdfIn PDF document text
    • http://hanilkwanla.com/uploads/files/zogiruberosule.pdfIn PDF document text
    • http://kulturazebrak.cz/userfiles/76354965407.pdfIn PDF document text
    • http://secretlove.ch/ckfinder/userfiles/files/soduzifof.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/55072a4000f3244338db30a632b517e5/40267226588.pdfIn PDF document text
    • http://sys-svinding.dk/userfiles/file/2456668755.pdfIn PDF document text
    • https://www.hagensmarketing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160804b4fc3725---jujabupimanuziloka.pdfIn PDF document text
    • http://hongshengfish.com/uploadfiles/2021061808153125773.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=need+for+speed+no+limits+mod+apk+offline+downloadPDF 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_off00010004.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10004 18432 bytes
SHA-256: 38b4d5bf1f533cda0f658599f30db32449c787b2710fff785d42657932a689b4
font_01_sfnt_off00012fb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FB7 10816 bytes
SHA-256: aab7e474fb0f8ff6ab4de27c6c765b4f97e828723626214a5483018dde1ee4a5
font_02_sfnt_off000148af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x148AF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1