Malicious PDF — malware analysis report

Static analysis result for SHA-256 5acebb961207b262…

MALICIOUS

PDF

82.0 KB Created: 2021-08-27 16:37:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 87c71d689e1e67bd0bf5bc0a61e7ea41 SHA-1: f78469690c4755d9844ebd42fd94a1bd0cb07c11 SHA-256: 5acebb961207b262413f0556a22deb49c71b43fcee7b3116b2d7af421eaaaff5
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URLs, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm or phishing lure. The malformed stream length heuristic indicates potential exploit activity within the PDF structure, possibly leveraging embedded JavaScript to redirect users to these external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://pixomot.ru/uplcv?utm_term=interview+questions+and+answers+for+html+and+css PDF link annotation
    • https://banghenails.com/upload/file/67177893499.pdfIn PDF document text
    • https://yziact.fr/wp-content/plugins/super-forms/uploads/php/files/k98jmjnofjh5blhli43bjp31of/14410562987.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16102d43c4a2ff---12530959318.pdfIn PDF document text
    • http://www.injamal.es/nueva/ckfinder/userfiles/files/fonimesat.pdfIn PDF document text
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/5d66fca99efc86948e4fee4e5decfbbd/41082883303.pdfIn PDF document text
    • http://enotecagaribaldi.it/userfiles/files/ratoxetilubomugatego.pdfIn PDF document text
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607877a9f3f2c---zepase.pdfIn PDF document text
    • http://sxhk365.com/uploads/file///96469649823.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/16114f696593a4---fipabuz.pdfIn PDF document text
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/dogexajikinogozoradef.pdfIn PDF document text
    • http://caopump.com/admin/userfiles/file/50774788031.pdfIn PDF document text
    • http://nsdadventist.org/FCKData/file/rigowavogari.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/ea141a4c86119a6f0fcfbe7e473d1342/dosazorafedumobolurupebuj.pdfIn PDF document text
    • http://santamariamikado.com/uploads/files/51102068659.pdfIn PDF document text
    • http://intrinhgia.com/admin/webroot/upload/image/files/1137382941.pdfIn PDF document text
    • https://hirurgija.me//files/wizinerifamu.pdfIn PDF document text
    • https://www.electriclighting.com/wp-content/plugins/super-forms/uploads/php/files/bc42845457ab5cb62fac92693881ab6c/silubonifafirurisujivub.pdfIn PDF document text
    • https://ezsprinting.com/userfiles/file/vuzemoredulagewud.pdfIn PDF document text
    • http://harchovyk.com/userfiles/file/30255426377.pdfIn PDF document text
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16083a9b69b1b4---43781471982.pdfIn PDF document text
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096b38653d1d---97192543820.pdfIn PDF document text
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607991823711c---73433421308.pdfIn PDF document text
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cebdeace224---jokuxetezinirigokepog.pdfIn PDF document text
    • https://mrmusicfoundation.org/wp-content/plugins/super-forms/uploads/php/files/e7qf8f2bv9rjarmnnbhg94r4br/99552308112.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c8fb5802b23---89417311265.pdfIn PDF document text
    • https://lesfeesdelhetre.fr/upload/files/90727878855.pdfIn PDF document text
    • http://shmountaineering.co.uk/wp-content/plugins/super-forms/uploads/php/files/ahqnl7oefgbear77uidreisc23/6590835467.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_off0000dc04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC04 17292 bytes
SHA-256: 2c9c6487c6fea2f1202b8e727418a603f4e9f41211badc7dbe2e3922a5f6023d
font_01_sfnt_off000108b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108B2 11088 bytes
SHA-256: 852b9fff8e66878d169476f3bb007916f041833c31ebe10523b8677b55a6cf1e
font_02_sfnt_off0001223d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1223D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1