Malicious PDF — malware analysis report

Static analysis result for SHA-256 8561972ec96e6bfc…

MALICIOUS

PDF

74.7 KB Created: 2021-09-22 15:03:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: abd8a6f945d6d310ca07db1c00331d80 SHA-1: 73748069bd7df84b010ed71146d2573e3464d404 SHA-256: 8561972ec96e6bfc27be163a9e5bb1893781cdcac61d6bd5ad027d332041abc8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. Heuristics reveal it functions as a link farm, directing users to various domains, including compromised WordPress uploads and disposable hosting, under the guise of a technical document. The presence of embedded URLs and the overall structure strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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
  • 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.
  • 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://oniceh.ru/uplcv?utm_term=schaum%27s+outline+of+thermodynamics+for+engineers PDF link annotation
    • http://americandeliorder.com/uploads/files/47935996413.pdfIn PDF document text
    • http://cbgnfinance.com/userfiles/file/paxozovojixuwa.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b430ccb54e---mepuxifili.pdfIn PDF document text
    • https://holcom-wd.holcom.vn/webroot/img/files/99329545949.pdfIn PDF document text
    • https://iieng.org/editor/ckfinder/userfiles/files/muxelemotes.pdfIn PDF document text
    • http://nscenter.cn/upload/files/57815650584.pdfIn PDF document text
    • https://sankaibearing.com/userfiles/files/rawivimodepajosipibavela.pdfIn PDF document text
    • http://xn--e1aazeoc7d.xn--p1ai/images/shared/file/zakofeguxutezitumoxojoge.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16132b13a5234d---92886403058.pdfIn PDF document text
    • http://antansconstructions.com/ckfinder/userfiles/files/lifegi.pdfIn PDF document text
    • https://skyzoan.com/cake/beta/userfiles/file/16874681787.pdfIn PDF document text
    • https://www.pollackmihalyiskola.hu/ckfinder/userfiles/files/97908275007.pdfIn PDF document text
    • http://jadeite.ru/images/file/kuxifi.pdfIn PDF document text
    • https://sanaspinler.com/calisma2/files/uploads/76469607904.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16146808c3d437---narebidadapazazomike.pdfIn PDF document text
    • https://braindevelopmentmaps-org.neurondevelopment.org/userfiles/files/diwefubulozoxufuzewol.pdfIn PDF document text
    • http://youzedu.com/ckimages/files/20210909070724434396.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16137891be0a1b---17066058446.pdfIn PDF document text
    • http://el-system.jp/uploads/2012/files/96488195952.pdfIn PDF document text
    • https://stomatoloska-ordinacija-rijeka.com/files/bumexafakamibex.pdfIn PDF document text
    • http://vln.nl/files/file/74301047675.pdfIn PDF document text
    • https://kimcert.com/E/file/nulinuvu.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_off0000bdf1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDF1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d608.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD608 11244 bytes
SHA-256: f7e3f1f011f74fa208039a2f76a37a1e16726ea1c965819b986886d059db36bf
font_02_sfnt_off0000f010.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF010 17316 bytes
SHA-256: 501000bc3d2f2917c9238354ba83df095997e59e3482deb9ab4b4ed84c223eb8