Malicious PDF — malware analysis report

Static analysis result for SHA-256 85b173f8587265bb…

MALICIOUS

PDF

107.2 KB Created: 2021-08-18 13:24:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 74b8ce8f710de12e1f46b73d46a94aa9 SHA-1: 75b2fa96711db075a23b0df36f36149d1884dc76 SHA-256: 85b173f8587265bb549751b31703f215e6ee8e8feeb64ad937c8c4e5c4f0195c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. It contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics strongly suggest an attempt to exploit users through deceptive links, likely as part of a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://ecobox.eng.br/wp-content/plugins/super-forms/uploads/php/files/4vhk8haphfnbbgh987u12i19cq/62098225953.pdf In PDF document text
    • https://latework.cz/soubory/nifazitogemajejixuza.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16099ab44bffed---gomajugifoxavow.pdfIn PDF document text
    • http://mebco.ru/images/file/86143193068.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160de47eb16b21---nujipezekizonomad.pdfIn PDF document text
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/471ec0af267fe89e3cd2167e660b25f9/mupepedo.pdfIn PDF document text
    • http://x04ydivan.ru/userfiles/file/39288677014.pdfIn PDF document text
    • http://ordineveterinarivenezia.eu/userfiles/files/12635948275.pdfIn PDF document text
    • http://henanshuangxin.com/d/files/faromibedepojumel.pdfIn PDF document text
    • http://ttmplus.com/userfiles/files/repatawifaxuxotilanaxigex.pdfIn PDF document text
    • http://pp-aqua.com/userfiles/files/faxireraxe.pdfIn PDF document text
    • https://hogies.com/includes/template/uploads/file/83963302950.pdfIn PDF document text
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/81375043e0e255e855d322e1b116a62c/25687739410.pdfIn PDF document text
    • https://metnar.pl/web/uploads/files/82066477061.pdfIn PDF document text
    • http://avtoarka.ru/wp-content/plugins/super-forms/uploads/php/files/3b88b7b138478b0c9750cedb014ccb1c/29112637890.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/lutexiri.pdfIn PDF document text
    • http://upbfassadenbau.com/upload/file/63068060137.pdfIn PDF document text
    • http://hoskinspugs.net/clients/40498/File/wivoweziwovu.pdfIn PDF document text
    • https://frontlinetherapist.com/wp-content/plugins/super-forms/uploads/php/files/02e477804a3d5eff2c5f178f22eb51a7/xaturoxef.pdfIn PDF document text
    • http://anbao.vn/uploads/userfiles/file/97314291076.pdfIn PDF document text
    • http://www.synagoge-stommeln.de/ckfinder/userfiles/files/xidiko.pdfIn PDF document text
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d5a8c87e8d---75826624456.pdfIn PDF document text
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/5b46fa38e7158d6de7ee38d027117546/4921942485.pdfIn PDF document text
    • http://reginahajo.hu/_user/file/33360971945.pdfIn PDF document text
    • https://vantainoidia.vn/ci/userfiles/files/1106767309.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=harry+potter+and+the+chamber+of+secrets+basilisk+victimsPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013920.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13920 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00015137.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15137 11288 bytes
SHA-256: 8785929f13938930915802ca064964a279c6d5807bbc46abc07d420db7eaf435
font_02_sfnt_off00016b44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16B44 20816 bytes
SHA-256: b521cf1210fe918985a2a5d9c3daf3bfe40575de98a7452b1893a73816367eee