Malicious PDF — malware analysis report

Static analysis result for SHA-256 1898dda87c458db9…

MALICIOUS

PDF

74.0 KB Created: 2021-09-18 15:29:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 4351900d3ef6b26c1a1e08da030e5e61 SHA-1: 1dea6fff6c379a9270dd74d0e99c8ee158bcfa8c SHA-256: 1898dda87c458db9ab659a0f5ee9e76415fd993da34803ed28627beed34c899f
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. The presence of embedded JavaScript and numerous external URLs suggests the PDF is designed to download and execute a second-stage payload or redirect the user to a phishing site. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports the phishing lure hypothesis.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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 https://tadimtursu.com/image/files/46076117798.pdf In PDF document text
    • http://chiangmaicharmingtravel.com/ckfinder/userfiles/files/gajusurujinipavu.pdfIn PDF document text
    • http://dentali.cz/files/files/lelumupobozolibafibe.pdfIn PDF document text
    • http://nghieuphong.com/upload/files/kufirepurutopizarirop.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/161415633a99ad---6602448845.pdfIn PDF document text
    • http://ldkxzzs.com/images/userfiles/file/lavid.pdfIn PDF document text
    • http://sprinter-lab.ru/content/File/84301445967.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161323a2d1788b---99902855591.pdfIn PDF document text
    • http://thesciencenetwork.org/uploads/files/43011546256.pdfIn PDF document text
    • https://wedding-photos.cz/userfiles/file/rasikidew.pdfIn PDF document text
    • http://gianphoiduyloimodel.com/Images_upload/files/68875202324.pdfIn PDF document text
    • http://www.skk.com.hk/admin/ckfinder/userfiles/files/fawawenarimusene.pdfIn PDF document text
    • https://thietkewebseo.com/webroot/img/files/butidipuxuna.pdfIn PDF document text
    • http://sistarelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/42304955616.pdfIn PDF document text
    • http://sdds.be/userfiles/file/48655421898.pdfIn PDF document text
    • https://daquin-ferriere.fr/userfiles/file/bukamujija.pdfIn PDF document text
    • http://ping-property.com/user_img/files/gijisarofabogigivuw.pdfIn PDF document text
    • http://vatlieulamnha.com/media/ftp/file/kagetimoxa.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1613b0e0481190---pevuxilisofajoluzoti.pdfIn PDF document text
    • http://fizjoactiv.eu/Upload/file/70684507171.pdfIn PDF document text
    • http://thesecurityguardunion.ca/userfiles/files/wusuwowunon.pdfIn PDF document text
    • http://fra2ange.it/userfiles/files/32128731620.pdfIn PDF document text
    • https://beamstraffic.com/amb/userfiles/file/puluvubuviteximiwatigader.pdfIn PDF document text
    • http://vsrru.ru/userfiles/file/10769133283.pdfIn PDF document text
    • http://www.artefuoricentro.it/js/lib/ckfinder/userfiles/files/19319132039.pdfIn PDF document text
    • http://heureka-cz.eu/files/nulesurulirasimixel.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=best+number+tracker+for+androidPDF 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_off0000be39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE39 10976 bytes
SHA-256: 738f5a5b92b85b104dad0092efe42fb5c97c130c0613ac4c0724eba5640f2cfe
font_01_sfnt_off0000d7ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7BA 16480 bytes
SHA-256: fdf56f5170e36965a4c22cf26a1c6608fcad9bbf2b952561e4534e11c9167088
font_02_sfnt_off00010204.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10204 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1