Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5233bf31a37e7b8…

MALICIOUS

PDF

86.6 KB Created: 2021-10-14 19:09:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: b78b122c7ae39e0ee1f3b854efd8f770 SHA-1: 5b52a714835933ba4a30c00e565a5389467be452 SHA-256: a5233bf31a37e7b85a01b7ceca5a6872c13be5aaab4095a862fc9e97132552e7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or are part of a link farm designed to obscure the ultimate destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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://gkz-crimea.ru/userfiles/file/juvavisaniribufofiwo.pdf In PDF document text
    • https://www.hkha.org/ckfinder/userfiles/files/69842934195.pdfIn PDF document text
    • http://gospel-pour-100-voix.com/fichiers/newsletter/file/29629168128.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16156ee69c807a---61786798226.pdfIn PDF document text
    • http://asvpp.fr/pdf/wapejuk.pdfIn PDF document text
    • http://sportgalaktik.sk/userfiles/file/45288455446.pdfIn PDF document text
    • http://sntaviator.ru/ckfinder/userfiles/files/xudanomusinegore.pdfIn PDF document text
    • http://ntep2008.com/UserFiles/File/muvagidixa.pdfIn PDF document text
    • https://uslugiinzynierskie.com/eurostyl/photos/file/64114716735.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613d120d09c97---xumuwoneba.pdfIn PDF document text
    • https://vaitinhdien.com/app/webroot/upload/files/81380479026.pdfIn PDF document text
    • http://growlink.biz/userfiles/file/dibativogurik.pdfIn PDF document text
    • http://easy-sleep24.de/shop/images/editorfiles/file/86168567405.pdfIn PDF document text
    • https://agencement-menuiserie-var.fr/stockages/files/32953387442.pdfIn PDF document text
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614824e35df61---mupegefaxe.pdfIn PDF document text
    • http://graficaeformazione.it/userfiles/file/napezedifepajavabul.pdfIn PDF document text
    • https://kettosallampolgarsag.net/imagini_ws/wijuduj.pdfIn PDF document text
    • https://123natura.com/stockages/files/mununulumipawizuwom.pdfIn PDF document text
    • https://kuepancong.com/contents/files/robufudeditul.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613751eb7bb3c---kasej.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/vItLtdF7Pec/uplcv?utm_term=celebrities+in+their+30sPDF 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_off0000ed30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED30 18660 bytes
SHA-256: ca5e8aadde62149077d2c539e528b28fe4f59f3044225ef95537d48be895e7b1
font_01_sfnt_off00011d87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D87 10388 bytes
SHA-256: ef55a772fc8bcb0c8e437cd2af2211f4636b0d144de1ad197e83a07ea4526540
font_02_sfnt_off000134fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134FE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1