Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cfbac0cf0617daf…

MALICIOUS

PDF

89.8 KB Created: 2021-08-13 08:46:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 3dee485d9fa1b16ca1dafe8c33fe41ca SHA-1: 0430be39677334ff4b6796dba0d4b3b926165594 SHA-256: 4cfbac0cf0617daf02718ff0d9a8a2969b18991aebae317d5d14d88b7990dbd7
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed for SEO poisoning or phishing. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true intent beyond directing users to external URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://ctyrkolky-gamax.cz/data/dokumenty/somegiwijewozuw.pdf In PDF document text
    • https://psychologgia.pl/Upload/file/ditisabumilapi.pdfIn PDF document text
    • https://akarchlight.com/wp-content/plugins/super-forms/uploads/php/files/535732099a294b9dbe088645d39bec4a/wozutazafijom.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/64774967691.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/mtlp0k3o0ktriqu744a5gku601/46332330530.pdfIn PDF document text
    • https://jairdefreitas.com/ckfinder/userfiles/files/xumibadoxagifajo.pdfIn PDF document text
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/160942bf9296b2---zanuxapa.pdfIn PDF document text
    • http://roomyab.ir/basefile/roomyabir/files/gotikujaj.pdfIn PDF document text
    • http://stin-verdon.fr/assets/Image//files/lalitosukezakim.pdfIn PDF document text
    • https://cls-toronto.com/wp-content/plugins/super-forms/uploads/php/files/6bf7834c26b6dba12af31431ffee2acd/juzabakokurisujagoledi.pdfIn PDF document text
    • https://samsungklima.net/upload/ckfinder/files/darovom.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1606f98130ba14---funosobowez.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/160af2796c0442---64444300307.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/qft3v6t407ecril97gp718hsk2/fogonu.pdfIn PDF document text
    • https://igruppe.no/ckfinder/userfiles//files/16459969885.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16095dc91cf5b4---10152348108.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160ba2c212d429---45156258632.pdfIn PDF document text
    • https://exxontel.com/file/90810843956.pdfIn PDF document text
    • http://dzbnf.com/upload/file///boguvotojidiferubewu.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/efeg6tvnj9s68rf8f5mnamslo2/82574818177.pdfIn PDF document text
    • http://youandisagenix.com/ckfinder/userfiles/files/33982915577.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c7804f73cad---86176860511.pdfIn PDF document text
    • https://travelstore.tn/userfiles/file/vumonezi.pdfIn PDF document text
    • https://epiphanych.com/images/file/81867459043.pdfIn PDF document text
    • https://pui-vital.ro/msg_media/file/redatu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=emotional+manipulation+techniques+pdfPDF 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_off0000fd29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD29 16560 bytes
SHA-256: 66fb1b3edaa4ffd75548029a04b1c717dae10c358bb19565dd3e58de2e4a7d55
font_01_sfnt_off000127f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127F2 11012 bytes
SHA-256: d1e7276a76746b040cafe12c62e61faa6e9afaea31935e3fceb863017145dc2a
font_02_sfnt_off0001411f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1411F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1