Malicious PDF — malware analysis report

Static analysis result for SHA-256 5163c4ac75293087…

MALICIOUS

PDF

71.2 KB Created: 2021-09-22 09:17:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 93c1fa1cd7d6ab2f8bd2849b2f467e78 SHA-1: 8aed67409abe3e53585d20f189222cf6c59826c8 SHA-256: 5163c4ac75293087e458bf54f8026175ca45fc823dc849eea614187299c68fa7
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which are part of a link farm hosted on compromised or disposable domains. The ML classifier strongly indicates malicious intent. The presence of JavaScript suggests an attempt to execute code, likely to redirect the user to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • 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=best+music+organizer+for+android PDF link annotation
    • http://www.protectakoteasia.com/ckfinder/userfiles/files/natovitikawujedomuriwaji.pdfIn PDF document text
    • http://evevoyance.fr/adh/.-/file/didiwagogujo.pdfIn PDF document text
    • http://toyotaprius-custom.com/js/upload/files/38725670103.pdfIn PDF document text
    • https://certifiedcollisionrepair.com/home/cert/public_html/ckfinder/userfiles/files/tulejumilixosupipolole.pdfIn PDF document text
    • http://glavis.biz/userfiles/file/15733900698.pdfIn PDF document text
    • https://quizai.com/uploads/files/noxafudeleboduzubakuba.pdfIn PDF document text
    • https://bahceneryaman.net/public/content-images/files/48152735989.pdfIn PDF document text
    • http://radiopoint.cz/userfiles/file/38568758477.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/gd6jab1vaq5m0ule7mi2lshk53/gafizotamimiwi.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/mcrhn1s94ugi1631bh15d0vom5/10829540855.pdfIn PDF document text
    • https://rubenferro.com/userfiles/file/rodapojijamipafetodivo.pdfIn PDF document text
    • http://lltsg.com/uploadfile/file///2021091303165785.pdfIn PDF document text
    • http://abwcockeysville.com/uploads/files/tetajamiwonaduxilowifape.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141f5e8b8cea---lugisorapilitugekagomejo.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/p6q5ruo8fstjvbnrlrblkbhrmr/melijaxuwefipomurerigaxel.pdfIn PDF document text
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/af581203a6279e697152c30b89ddb055/fobenafilakosafabu.pdfIn PDF document text
    • https://thieumaunao.vn/workspace/develop/uploads/ck_upload/files/dejuv.pdfIn PDF document text
    • http://akkoryazilim.com/userfiles/file/88539985914.pdfIn PDF document text
    • http://goldstecq.com/userfiles/file/81819329442.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ac99dbba42---zutetetaxuzonob.pdfIn PDF document text
    • https://ecoverservice.be/gallery/file/jefof.pdfIn PDF document text
    • https://eminentland.com/admin/userfiles/files/77479363394.pdfIn PDF document text
    • http://gattoneva.pl/pages/userfiles/file/fitadijitedawalo.pdfIn PDF document text
    • http://agro-partner.com/Image/files/tukezepuzekadux.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_off0000b696.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB696 15456 bytes
SHA-256: baa0c0b8bf4a2191f977b9c2bf0298c87bc2d549f859153f5b8a7198802540ae
font_01_sfnt_off0000dd68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD68 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f57f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF57F 10988 bytes
SHA-256: d08347bdef9acb52987244eb9f6f3d28dab2428032c6d5807c84ace487616f37