Malicious PDF — malware analysis report

Static analysis result for SHA-256 c53be963cd61cf7c…

MALICIOUS

PDF

73.4 KB Created: 2021-09-24 15:55:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: ef1246619763a711b38a1b88b9152e79 SHA-1: f95d28b16a0dcb05c3a2e1e3fe3664ad48062601 SHA-256: c53be963cd61cf7c9a17ff9290a0bcc1a213619a5924a6f2ec728f663bbff8dc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm directing to multiple domains, including one hosted on a compromised WordPress site. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it's designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 http://kammed.com/userfiles/file/25912293596.pdf In PDF document text
    • http://www.omt.ntou.edu.tw/ckfinder/userfiles/files/repowegozo.pdfIn PDF document text
    • http://www.bash.cl/media/file/kisezudivo.pdfIn PDF document text
    • http://kahounova.cz/userfiles/file/67311655885.pdfIn PDF document text
    • http://avandcie-energy.fr/ckfinder/userfiles/files/nazonebidos.pdfIn PDF document text
    • http://umffz21.ru/admin/ckfinder/userfiles/files/89801942566.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614634639c715---94838009734.pdfIn PDF document text
    • http://aygroupmuh.com/image/files/28504979522.pdfIn PDF document text
    • http://gmei.lt/ckfinder/userfiles/files/56477880954.pdfIn PDF document text
    • http://neoneofytou.com/ckfinder/userfiles/files/guxevifozubipa.pdfIn PDF document text
    • http://montex.pro/uploads/userfiles/file/nufalezixifujunufidalonew.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613aaf58e33aa---65484335141.pdfIn PDF document text
    • https://strategieb2b.com/userfiles/file/regogemepebeboxakezakomew.pdfIn PDF document text
    • http://smsalumni1971.com/apadmin/uploads/userfiles/files/45363919113.pdfIn PDF document text
    • http://www.tecnologycenter.com/admin/uploaded/fck/file/masijojipezivulaturetawi.pdfIn PDF document text
    • https://em.heephong.org/ethnicminorities/cmsadmin/ckfinder/files/morajozizuvuzopug.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613b3ef48b1eb---xusawufiluxo.pdfIn PDF document text
    • http://andersonlawdecorah.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/matulobobuxajonu.pdfIn PDF document text
    • https://swalaya.in/userfiles/file/wagasoju.pdfIn PDF document text
    • http://onroerendgoedindex.nl/images/uploads/kegunox.pdfIn PDF document text
    • https://wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/22632226610.pdfIn PDF document text
    • https://hoangvan.vn/wp-content/uploads/files/nudurijekozuj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=virtual+trackpad+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_off0000b8be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8BE 10476 bytes
SHA-256: 1f832eb5033a443a69d5a52efd93c9983a1e9cb879d2140b1372b43c462cbfd5
font_01_sfnt_off0000d0a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0A6 18240 bytes
SHA-256: 49fe9a0b7782086359b721c0f5f0a27b9dcd052db750a7c8f3a70f22007a1741
font_02_sfnt_off0000ffd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFD5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1