Malicious PDF — malware analysis report

Static analysis result for SHA-256 29692bc6cb2c753f…

MALICIOUS

PDF

68.4 KB Created: 2021-06-21 05:23:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 7a475b827f60e48eb0ae93902abdadaf SHA-1: a331f532bbd8bd5b8d10069f8c6ce92e78bf15cd SHA-256: 29692bc6cb2c753fd7de4730370ac86a54f3c0e8569651f92046cd95519968f1
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The document body, though partially corrupted, contains text suggesting a lure related to a quiz question. Numerous URLs are embedded, many pointing to compromised CMS uploads or disposable hosting, which are common tactics for phishing or malware distribution. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports the attack pattern of using link farms for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://infrive.ru/uplcv?utm_term=which+of+the+following+statement+is+true+for+pure+substance PDF link annotation
    • https://hitourkorea.com/FileData/ckfinder/files/20210616_07456EEF756B7A91.pdfIn PDF document text
    • http://vankouwenenmastop.nl/UserFiles/file/wufofikatesukegurosos.pdfIn PDF document text
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b1019fc5cec---47395400863.pdfIn PDF document text
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/vduiojoeps8h3rmc5o9a22m2n0/17990459509.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a79ec60a312---jixizixinasebutodukod.pdfIn PDF document text
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/eefq14hstrdcrmnimhkg1ninpv/migusedezozutaka.pdfIn PDF document text
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c9ee0434a7---30603129639.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/3e81a0787d58cb2b5e3ca0ff4b6fc684/13311288992.pdfIn PDF document text
    • https://actioncoach.com.my/wp-content/plugins/formcraft/file-upload/server/content/files/16075a98855585---51513022078.pdfIn PDF document text
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/43742327256.pdfIn PDF document text
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/d25873b06291641931e8dde3b2c79d9b/sikesunuzibolebusutiji.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160980f354eaa4---72144910783.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/tul2n1u6q47gla0o7iu1q9b274/49159702771.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7b3416f219---48288036873.pdfIn PDF document text
    • https://luxartparquet.com/wp-content/plugins/super-forms/uploads/php/files/92705ee6ae96611e0eab7dc52a8db9b1/vikaj.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f2691e504e---39643274573.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cba6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBA6 5676 bytes
SHA-256: a524683655406d4623a247352f3c549f7076d4c9f6e29e10480523274ba6686b
font_01_sfnt_off0000deea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEEA 11024 bytes
SHA-256: b8bc8d0542cd432be0660d9f858540dd9d9163d85791fd3bdee30d042aac4fd8