Malicious PDF — malware analysis report

Static analysis result for SHA-256 87a0937309260a5e…

MALICIOUS

PDF

84.0 KB Created: 2021-09-17 09:55:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5bb011fefd5e5eeb74b3fb63458647a5 SHA-1: 5169569ad251ef9afcd1a45ef8f92cd67aeba33a SHA-256: 87a0937309260a5ee8abad1e70e57d2b951d299b739dbf52e0f6219ad9287ef9
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO poisoning campaigns. The embedded JavaScript may be used to further obfuscate the malicious links or initiate a download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • 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.
  • 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://laborke.ru/uplcv?utm_term=thailand+vpn+free+apk PDF link annotation
    • https://pielinks.com/UserFiles/file/senuvazinizaxilaga.pdfIn PDF document text
    • https://aglogistics-bo.net/userfiles/file/vuvefewoxajufogafazuragop.pdfIn PDF document text
    • http://www.jacenter.org/js/ckfinder/userfiles/files/bupadoretuku.pdfIn PDF document text
    • http://www.fishandcosolicitors.com/uploads/files/731950329.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/56ba18185b98a32c3a8e0f7538178ad8/zizotozeduv.pdfIn PDF document text
    • https://capitalsyndic.com/userfiles/file/84387714181.pdfIn PDF document text
    • http://zulassung4you.de/bilder/file/legux.pdfIn PDF document text
    • http://stellarp.com/userfiles/files/92275978220.pdfIn PDF document text
    • https://vocembalo.ch/userfiles/file/gukakibimisedawa.pdfIn PDF document text
    • http://magooferta.pl/uploads/fck/file/denapuboguponadoku.pdfIn PDF document text
    • http://livelyway.com/ckfinder/userfiles/files/bodewazuvilamoxuv.pdfIn PDF document text
    • http://iccarrentals.com/files/file/66229950960.pdfIn PDF document text
    • http://mayphatdienngocquang.com/media/ftp/file/64177254180.pdfIn PDF document text
    • https://pepinieramontana.ro/ckfinder/userfiles/files/xapawu.pdfIn PDF document text
    • http://findacommodity.com/upload/file/39396777759.pdfIn PDF document text
    • https://regiefranchet.fr/userfiles/files/36151151571.pdfIn PDF document text
    • https://lionkingbali.com/uploads/file/letarit.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613648776dca9---lusefuxodosositupimaj.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132bcdb87060---60149544952.pdfIn PDF document text
    • http://exima.kr/userData/board/file/vupudakimisemajewes.pdfIn PDF document text
    • http://rocincorporated.com/domain.com/images/dynamic_pages/file/60781140227.pdfIn PDF document text
    • https://asken.as/bilder/file/datifujatusikurudikavifid.pdfIn PDF document text
    • https://karinbentum.nl/uploads/file/fixelivotag.pdfIn PDF document text
    • 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_off0000e039.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE039 10328 bytes
SHA-256: 9e8227c9ef2dc05b098f2f6add309606eb4c67b2fe62956428974385956847bd
font_01_sfnt_off0000f75a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF75A 19524 bytes
SHA-256: 7b9678768829845e2492dc87155ceb6d1ba94b8b7fe35319f4ee84e843e1357f
font_02_sfnt_off00012a63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A63 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1