Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ed774a2d4c88091…

MALICIOUS

PDF

69.6 KB Created: 2021-10-03 21:49:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: ff3f6427d9c76427522ac5f5fd3b0dcc SHA-1: c63dca5b2547486db3b96b6d41cf36f7e260068c SHA-256: 4ed774a2d4c88091d5065d6a3f51f9651c9317cdaba2d9123e466341768df2aa
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to PDF files hosted on various domains, some of which are potentially compromised CMS upload directories. This suggests a phishing or malware distribution campaign where the document serves as a lure to external malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • 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.
  • 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://www.tunnel.de/files/uploaded/file/damadomitub.pdf In PDF document text
    • http://divelife.kz/files/file/sitikobanuw.pdfIn PDF document text
    • http://aliceinformaticasrl.com/user/pages/tuxolegokug.pdfIn PDF document text
    • http://mellorymotors.ru/admin/ckfinder/userfiles/files/37654129041.pdfIn PDF document text
    • http://korealabels.com/ckfinder/userfiles/files/12683297100.pdfIn PDF document text
    • http://electrogalicia.com/electrogalicia/recursos/archivos/81345760016.pdfIn PDF document text
    • http://virus-safe-zone.com/ckupload/files/35429796530.pdfIn PDF document text
    • http://smartvoicecom.com/userfiles/dalim.pdfIn PDF document text
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132f95b1c739---totamafogerafuzub.pdfIn PDF document text
    • http://bluestandard.pl/ckfinder/userfiles/files/lerusurovitokoletoragofuz.pdfIn PDF document text
    • http://mydreamtuscanwedding.com/editor_up/98815026728.pdfIn PDF document text
    • http://volareinmongolfiera.it/userfiles/files/ruzozu.pdfIn PDF document text
    • http://asja-doll.ru/userfiles/file/vetotivuzarave.pdfIn PDF document text
    • https://www.lorenzofranzone.it/wp-content/plugins/super-forms/uploads/php/files/41697058f060f50d50c1ceed5c2d3d83/51256832603.pdfIn PDF document text
    • http://pc580.cn/upload_fck/file/2021-9-6/20210906011753268018.pdfIn PDF document text
    • http://0225674989.kad.tw/kads/ckfinder/userfiles/files/polubeju.pdfIn PDF document text
    • http://charolais-hessen.de/write/userfiles/file/bexovofe.pdfIn PDF document text
    • https://fundacjaartfreeart.pl/userfiles/file/korifix.pdfIn PDF document text
    • https://njshore.drinkpoint.com/uploads/files/pedegaxikutugotiguretige.pdfIn PDF document text
    • https://samsungdvmklima.com/upload/ckfinder/files/lejuxo.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613135fdd132b---81948510004.pdfIn PDF document text
    • https://hmjrgoldhockey.org/wp-content/plugins/super-forms/uploads/php/files/769db74b6833487747c8f4ef5dbc44a6/14500297729.pdfIn PDF document text
    • https://binarbaidservices.com/public_html/userfiles/file/29351280827.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b35eb8b988---vixigosukawaruw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=redirect+to+another+page+in+javascriptPDF 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_off0000b07d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB07D 10988 bytes
SHA-256: cd6cd02118ace3db4c6b029ee30bccbc5dcb644677a13e39a2b7ac605e8b5f14
font_01_sfnt_off0000c9b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9B3 15504 bytes
SHA-256: e71ba9375590ca33cc835937cd899506a15e11ef992abf6d79032b13d5e28170
font_02_sfnt_off0000f0bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0BB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1