Malicious PDF — malware analysis report

Static analysis result for SHA-256 624da8dd1670b309…

MALICIOUS

PDF

77.6 KB Created: 2021-09-22 15:57:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: dd1b7873c5abfbb58a92e7d033f9eea7 SHA-1: 4b192fc030e47b9eba97f9c84bb74cbe3e4bfb9d SHA-256: 624da8dd1670b30958c5a14eb815d052d078cc703e7a1c74bd342f13b5860d25
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS upload directories and disposable hosting, suggesting a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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 https://philabc.ru/uplcv?utm_term=video+call+from+iphone+to+android PDF link annotation
    • https://salvatoredivilio.it/userfiles/file/14294776952.pdfIn PDF document text
    • https://maisonforville.be/documents/file/8653506997.pdfIn PDF document text
    • http://ihanzao.com/userfiles/file/20210919123656_1588919690.pdfIn PDF document text
    • https://muahohangnhat.com/app/webroot/uploads/files/60018891185.pdfIn PDF document text
    • http://ff-engineering.com/userfiles/files/79965806025.pdfIn PDF document text
    • http://andersonlawdecorah.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/17855734568.pdfIn PDF document text
    • http://montagnobozzone.it/userfiles/files/12959182296.pdfIn PDF document text
    • http://peter-scherer.de/userfiles/file/64670734311.pdfIn PDF document text
    • http://constantemails.com/userfiles/file/1632093323nejir.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed61e4df05---37598608330.pdfIn PDF document text
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b18f0e84a4---70973526894.pdfIn PDF document text
    • https://salvamontbihor.ro/app/webroot/files/userfiles/files/sosomegezetomoxilu.pdfIn PDF document text
    • https://anaksemut.com/contents/files/22719908502.pdfIn PDF document text
    • http://polyacer-ecp.com/userfiles/files/20210912_042412.pdfIn PDF document text
    • https://hediyelikhanem.com/calisma2/files/uploads/tiridaz.pdfIn PDF document text
    • https://www.lipca.com/ckfinder/userfiles/files/28995207480.pdfIn PDF document text
    • http://shimamura-mail-order.com/userfiles/file/46784199634.pdfIn PDF document text
    • http://veterina-hrib.cz/user-uploads/files/mixigaj.pdfIn PDF document text
    • http://autodilykanka.cz/cmsimple/images/file/kobisisalixenuxonimar.pdfIn PDF document text
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161311207028cc---jejiveselizevu.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_off0000cbda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBDA 10684 bytes
SHA-256: 8a2c0b7be88c81b6fd6e73af889c3a3bf13ef6c6920dd34bfc1208c1dcfcd434
font_01_sfnt_off0000e412.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE412 17536 bytes
SHA-256: a8367dd6bffa030f6fcc6e53793b6293094b51a7808985190890d0f3f2a6f0c1
font_02_sfnt_off000110d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110D8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1