Malicious PDF — malware analysis report

Static analysis result for SHA-256 66be910284bad3d6…

MALICIOUS

PDF

69.3 KB Created: 2021-09-05 18:58:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: dbe5396ce6567fce8ad956828e348bcb SHA-1: 5019b6258768d03da62cd661cc1ac167664900b4 SHA-256: 66be910284bad3d64c0c4fdc0cd96ede9833ea6c6ca38e754b2025672ba23a1a
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing embedded JavaScript and multiple external URIs. Several heuristics indicate the PDF is part of a link farm hosted on compromised WordPress sites, likely designed to redirect users to malicious content or phishing pages. The ClamAV detection and ML classifier strongly suggest malicious intent, consistent with a phishing or trojan delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://krisoc.ru/uplcv?utm_term=demonata+blood+beast+pdf PDF link annotation
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16094dd3c25d5b---31985519725.pdfIn PDF document text
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078914cb5792---zuxupadimuxijomutaditak.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa8fb910403---wegakojifilil.pdfIn PDF document text
    • https://xn----7sbbjg7ctfs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/50b78b609a1e051ea0ccc00cffe0e438/dinebamon.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160af3a194c274---62290083746.pdfIn PDF document text
    • https://salvatoredivilio.it/userfiles/file/72104497584.pdfIn PDF document text
    • http://traktorpulling.de/ablage/userfiles/files/66697139185.pdfIn PDF document text
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/160838c45f39e4---18846819996.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070c72844c06---91053419939.pdfIn PDF document text
    • https://greshamgilessalon.com/wp-content/plugins/super-forms/uploads/php/files/d4cc7a5cbf8d51ad449a05fa92beb2b1/30780432098.pdfIn PDF document text
    • https://universitecentrale.net/uploads/FCK_files/file/gatutasetokabatoku.pdfIn PDF document text
    • http://transinfosoft.com/userfiles/file/dipunisajukemi.pdfIn PDF document text
    • http://sowitech.vn/upload/files/fogoj.pdfIn PDF document text
    • https://seeandhearbetter.ie/img/shop//contents/xasiveladowebasaxajewofal.pdfIn PDF document text
    • https://motacademy.it/file/bumegekokijobigi.pdfIn PDF document text
    • http://belloverde.net/emailer/file/gojotasininuwog.pdfIn PDF document text
    • https://konferencii.ru/js/ckfinder/userfiles/files/doguduxujit.pdfIn PDF document text
    • https://luxartparquet.com/wp-content/plugins/super-forms/uploads/php/files/fde1fd828f6e080b74f073b01f14b606/96576787040.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/mg0jq5kq7iov3nesn2jnujagr3/vamisinubejiz.pdfIn PDF document text
    • http://apluskleaning.com/admin/images/file/jiridezejanukuwomixezil.pdfIn PDF document text
    • https://www.asahinadigital.com/wp-content/plugins/super-forms/uploads/php/files/4ujq8fsvb1p2t9aslqp4f4j704/bosix.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609ba15c243f5---5195544914.pdfIn PDF document text
    • http://amirafouad.com/uploaded_files/file/jexebevi.pdfIn PDF document text
    • http://praconsulgroup.ru/pict/file/98453505407.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_off0000b39e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB39E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cbb5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBB5 10608 bytes
SHA-256: 28b8faf845cb8a5ead3628e92ff802c1a9f025e40224c8203e6c5f8801269121
font_02_sfnt_off0000e3b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3B7 14504 bytes
SHA-256: 65df1492bc237662b17794ba6cd21cbfe49e1e00cfdab1281a0a9463dea8655c