Malicious PDF — malware analysis report

Static analysis result for SHA-256 1936b3ba6a92603d…

MALICIOUS

PDF

87.6 KB Created: 2021-09-03 21:45:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 33e637741ba068ecc4590f73666214e7 SHA-1: ad89bded941e8b36744b43bcba8de47fe5eaac01 SHA-256: 1936b3ba6a92603d2b950de1d6206e27e3b2e5b6c006180b6ff1b0f1e027367e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF identified as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many pointing to compromised CMS upload directories, suggesting a link farm designed to redirect users to malicious content. The presence of PDF-specific heuristics like 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://www.schroedersales.com/wp-content/plugins/super-forms/uploads/php/files/5f16f35b113617d8a1e8be9039cdd0f0/66870371401.pdf In PDF document text
    • http://sanitaerprofi.ch/fckeditor/editor/images/file/lutunigoni.pdfIn PDF document text
    • http://vagtteam.com/userfiles/Files/vovomurufigurekorifom.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/d183dfa7c1992907ec2a69cf508c5a67/kalujutafigidudul.pdfIn PDF document text
    • http://www.festivalmarrakech.info/wp-content/plugins/formcraft/file-upload/server/content/files/160cb4c649756f---xuzexixiwuvupejepe.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/33037780791.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4c4b1535e6---14051815829.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/q3pac5fob03kd99pg1c8ob3a05/fogedepepenawinerepiku.pdfIn PDF document text
    • https://vdbergelectro.nl/wp-content/plugins/super-forms/uploads/php/files/9a58e365cf3639117e0406734127551a/18667627004.pdfIn PDF document text
    • http://allaboutdowney.com/userimages/61858345315.pdfIn PDF document text
    • http://pobierzplik.pl/uploads/files/jozawov.pdfIn PDF document text
    • http://jyjwqj.com/uploadfile/file///2021052116571837.pdfIn PDF document text
    • http://www.aceitunasdelguadalhorce.es/ckfinder/userfiles/files/dolerifoxirusuragix.pdfIn PDF document text
    • https://pestresolution.pt/site/upload/file/82574221429.pdfIn PDF document text
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/1607119a2e8730---kapujeku.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160edc3f829166---mademuxoj.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f820989378---lukiro.pdfIn PDF document text
    • http://otvorene-srdce.sk/userfiles/file/21609539502.pdfIn PDF document text
    • http://farmaciacogliate.it/userfiles/files/wedogaxusi.pdfIn PDF document text
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160784bde6f074---tosixexekowevuridusib.pdfIn PDF document text
    • https://biserica-izvorul-tamaduirii.ro/files/11339843120.pdfIn PDF document text
    • https://robotics-institute.com/wp-content/plugins/super-forms/uploads/php/files/q5doc1c06g5716dp19mrgcae9j/65351217657.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160704155141d4---41388730257.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/096d0316a3a51e210a5612b70047b282/ruradudotimovuxaweva.pdfIn PDF document text
    • https://vetranhtuongmamnon.vn/wp-content/plugins/super-forms/uploads/php/files/dkqtk6qnm3sa35p74l9355qeng/kosotigatazivaniro.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=marvel+avengers+infinity+war+comic+pdfPDF 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_off0000edab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDAB 18640 bytes
SHA-256: 23cdca9cdcf59a3f3a7b406aaea46a24009f00893097a3432f9b874ee8371ea8
font_01_sfnt_off00011e5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E5D 11220 bytes
SHA-256: 43d25cb490754477b804945aedcf5dac2bf0d750ff56252d925ab3716c0b84f4
font_02_sfnt_off00013889.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13889 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1