Malicious PDF — malware analysis report

Static analysis result for SHA-256 c31a868cef6f9624…

MALICIOUS

PDF

81.5 KB Created: 2021-08-24 19:31:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 176508d60fa9ddaeda34adb48b6e72c3 SHA-1: c5d662d14b73c6b7c920f4a61dc69bf3e62878ba SHA-256: c31a868cef6f96245c1a6f0ce9a34985c9abf694ffccede83d29c05f29319f67
156 Risk Score

Malware Insights

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

The PDF file contains a large number of links, many pointing to compromised WordPress upload directories, indicating it functions as a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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 http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082ec800e001---vagup.pdf In PDF document text
    • https://amursvoidom.ru/media/files/fulofivavedegisiwejanutu.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/351980241.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/16085720b5b969---nazegalegiwekanuwaf.pdfIn PDF document text
    • https://gastrotest.co/ckfinder/userfiles/files/62120282643.pdfIn PDF document text
    • http://cualuoiskydoor.com/webroot/img/files/boxixirebepotuwolovi.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/2ec75ac076e706b912f1328604fd492f/95628702465.pdfIn PDF document text
    • http://2girlstrippin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d2a6abb55df---govezovenavetibivejifiv.pdfIn PDF document text
    • http://cfacgroupe.com/uploads/FCK_files/file/puzixonabuxenezitezizuves.pdfIn PDF document text
    • http://yuha.be/_files/file/fajulojokifofiweremazef.pdfIn PDF document text
    • https://kultmotor.hu/images/files/84664718001.pdfIn PDF document text
    • http://sampoernastrategic.com/uploads/image/files/wafuzobuladafefesep.pdfIn PDF document text
    • http://glovimex.com/uploads/ckfinder/files/4546239079.pdfIn PDF document text
    • https://cal.lighting/wp-content/plugins/super-forms/uploads/php/files/62e46fae1f29eda0c5ea351197a58d89/nowapimuduretogok.pdfIn PDF document text
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/fe7bafc12491810157bf47e055ad55c0/sopawojiritiv.pdfIn PDF document text
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160ac21845e91e---75980010879.pdfIn PDF document text
    • http://grandp.ru/userfiles/file/pipofegamurago.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/tuvopupufevunusam.pdfIn PDF document text
    • http://lyzjkgm.com/d/files/lazesiloti.pdfIn PDF document text
    • https://catherinehourihan.art/wp-content/plugins/super-forms/uploads/php/files/ec2a4beebba3999df63e4d4825bd3b4b/dofeg.pdfIn PDF document text
    • http://humanlitech.com/files/files/vuwatisikazebupopovol.pdfIn PDF document text
    • http://atenngo.com/admin/sites/site/documents/13313043141.pdfIn PDF document text
    • http://ibshop.gr/uploads/_uploads/files/putaxizenuxomelop.pdfIn PDF document text
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/43bc817ade2aef7e63be96e6f1d04963/82062077716.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=doctor+faustus+notesPDF link annotation
    • https://mediaget.com/userfiles/files/37889442413.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_off0000dc33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC33 16996 bytes
SHA-256: 69afb5d1e081b73f80470f5cd10d1dbdc7714e9d26995579dffc5db306bcf4f1
font_01_sfnt_off00010893.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10893 10292 bytes
SHA-256: d6924911f577f4aeba856f512cf6c80e5f8af63a8220e8734ce6257c74fc9f84
font_02_sfnt_off00011ff0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FF0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1