Malicious PDF — malware analysis report

Static analysis result for SHA-256 35cbbbb7bd2b05e1…

MALICIOUS

PDF

84.0 KB Created: 2021-09-09 14:11:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4353ea3ceb1f02e4a94e35f151b8e636 SHA-1: 099483d3ccc3f668710a213d71175fda4a9817e6 SHA-256: 35cbbbb7bd2b05e17b61a9cfc1597c904cdb9ecce86af3daae04f6b549ef0f62
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to compromised CMS uploads and disposable hosting, indicating a phishing or redirection attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to deliver a secondary payload or phish users. No scripts were extracted, limiting the analysis of specific execution methods.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://wo-kop.pl/userfiles/file/75496751275.pdf In PDF document text
    • http://fu-xin.tw/uploads/files/202109070209211201.pdfIn PDF document text
    • http://polyacer-ecp.com/userfiles/files/20210908_160535.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131f4ab0b483---27092632091.pdfIn PDF document text
    • http://mistral-paints.cz/userfiles/files/bixazavifasomaxekilamozu.pdfIn PDF document text
    • http://qhzs88.com/admin/fckeditor_upfiles/file/2021090915175080554.pdfIn PDF document text
    • https://learningsolution.ca/userfiles/files/1095085235.pdfIn PDF document text
    • https://pelletier-tp.fr/ckfinder/userfiles/files/dusifu.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/37db21a95aac4c0ab3dcd100e4760a1e/gorizudabijuregexarila.pdfIn PDF document text
    • http://domexpo.ru/up/file/8092518946.pdfIn PDF document text
    • https://sitarasign.ir/data/file/95219535427.pdfIn PDF document text
    • https://dildendilecevirievi.com/upload/ckfinder/files/bojigekalexazukinegitavep.pdfIn PDF document text
    • http://bachova-terapia.sk/images/file/gibuzugonogutitizokuwo.pdfIn PDF document text
    • https://sgcaregiver.org/contents/files/58305918046.pdfIn PDF document text
    • http://larben.cz/media/images/upload/file/355422309.pdfIn PDF document text
    • http://orosweb.hu/ckfinder/userfiles/files/wemokajopevalikunaz.pdfIn PDF document text
    • http://pro-elec.ru/ckfinder/userfiles/files/bizakesalo.pdfIn PDF document text
    • https://copperscraphandlers.com/ckfinder/userfiles/files/72694215162.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613108c1779e6---vudorulibikexisedu.pdfIn PDF document text
    • http://saveursetsavoirs.fr/image/file/93203585749.pdfIn PDF document text
    • http://fgsconsulta.com.br/ckfinder/uploads/userfiles/files/95558197626.pdfIn PDF document text
    • https://tutorlookup.com/ckeditor/ckfinder/userfiles/files/desofiginuwiteta.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=no+sim+detected+androidPDF link annotation
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/161388ff526a2f---disezogevomori.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_off0000e1b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1B5 19052 bytes
SHA-256: e7e155876b64e1bb63bc9b3717d3becbc9d3d9cadb582761e77698ec7b9d1300
font_01_sfnt_off000112d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112D3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012aea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AEA 10464 bytes
SHA-256: 832a5a660a6b0044dcd37d3a053850aa1ea6b065915dddbb3e3e8116c701fdb5