Malicious PDF — malware analysis report

Static analysis result for SHA-256 1643cf50b52d653b…

MALICIOUS

PDF

96.3 KB Created: 2021-08-05 17:29:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: a38f85cf9cb20dcf0511bf508bf69451 SHA-1: 5c882c264fe995618fb26a58cec3ee4530d5bccf SHA-256: 1643cf50b52d653be1e86c4986c869ad9d5a58742f0cbb3b2f8de89adae3802c
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to websites hosted on compromised CMS uploads and disposable hosting, indicating a link farm designed to redirect users to potentially malicious content. ClamAV detected this file as Pdf.Phishing.Trojan, and an ML classifier also flagged it as malicious. The presence of these links suggests an attempt to lure users to external sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607d2a3e9085e---xetotunalerobex.pdf In PDF document text
    • http://kaitosushisb.com/uploads/files/74710482060.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab3db8203b4---13615579806.pdfIn PDF document text
    • https://ehblending.com/wp-content/plugins/super-forms/uploads/php/files/76ef362dc922b7db659810830f3c6ed9/46795027553.pdfIn PDF document text
    • https://asiajitu.com/contents//files/4734068013.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c87b5922182---26983288474.pdfIn PDF document text
    • https://yellowstonewildlife.com/8520096054.pdfIn PDF document text
    • https://podimercrm.com/img/files/99044958854.pdfIn PDF document text
    • http://wernersuarez.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/68353764838.pdfIn PDF document text
    • http://sterkrade.net/ckfinder/userfiles/files/53750502069.pdfIn PDF document text
    • http://melvin.cz/data/faxesigoditajenotakozifa.pdfIn PDF document text
    • http://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/8fba97f8d8610437cc89ecc6f2464247/82328536464.pdfIn PDF document text
    • http://sentralperdana.com/file/9332915919.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/92129266350.pdfIn PDF document text
    • https://digbijoynath.in/iisc/ckfinder/uploads/userfiles/files/62487472276.pdfIn PDF document text
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160987c06dc478---tabetuwigi.pdfIn PDF document text
    • http://aire-limpio.com/img/editor/file/16710193571.pdfIn PDF document text
    • http://4x4autok.hu/userfiles/files/55783717972.pdfIn PDF document text
    • http://dtpokebar.com/uploads/files/53095719516.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/160756ad587b40---58025370344.pdfIn PDF document text
    • http://eurogeographyjournal.eu/admin/fckfiles/file/97955024575.pdfIn PDF document text
    • https://proxus.nl/file/jipibawuxezugurufuka.pdfIn PDF document text
    • https://detectiveoffice.net/userfiles/file/papirudenekidegovumuvod.pdfIn PDF document text
    • http://alexhoffordphotography.com/temp/files/file/98804775811.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=what+are+the+disadvantages+of+term+life+insurancePDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fed2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFED2 11084 bytes
SHA-256: 6f5ce6a87a3f4b9d548542ced97f5f1727904dfa348667ec3d5fe48c824a38c0
font_01_sfnt_off0001184e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1184E 17044 bytes
SHA-256: e6972d43fc8457eb8d9bd950374be0fbd71c1b211f24e5924609d042f679dcef
font_02_sfnt_off000144c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x144C4 16140 bytes
SHA-256: 00b1f632e8afe72716c8bcdb76b7901b56c060d1dc0f96f3f5c1b8373b85735b
font_03_sfnt_off00015a40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15A40 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1