Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5bd63f85acb327a…

MALICIOUS

PDF

76.9 KB Created: 2021-09-19 06:27:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 9fd4f525dad8ecd9ce993f70f076e7e7 SHA-1: 5cfc414fd2f9512854810849be870d7e22534dc9 SHA-256: a5bd63f85acb327a83ef9496201bbe50b61589efba9b06818e9970a91ce5b33f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous embedded URLs that point to compromised CMS upload storage and disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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 https://smidgel.ru/uplcv?utm_term=c%2B%2B+in+depth+pdf PDF link annotation
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/d15fgt2ldbujpi00kt0h7nofi6/muxedalemuj.pdfIn PDF document text
    • http://georgewongdesign.com/gwd/upload/files/87369105409.pdfIn PDF document text
    • http://ledins.lv/cms/file/87299167163.pdfIn PDF document text
    • http://proallprint.com/userfiles/files/rerawawufekepat.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cd8eea03af---50283844706.pdfIn PDF document text
    • http://parcroyale.hk/userfiles/sugutob.pdfIn PDF document text
    • http://metamorfozyayincilik.com/userfiles/file/takeluzopu.pdfIn PDF document text
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/6ddcccf18b4a3fe434bcddf713e60918/52470220559.pdfIn PDF document text
    • http://porpora.biz/imagenes/imagenes_contenidos///xibafutujunibexowujirase.pdfIn PDF document text
    • http://bsinteriordesigner.com/userfiles/files/65767174155.pdfIn PDF document text
    • https://wilocom.ro/ckfinder/userfiles/files/23059069593.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/16137cd0515140---69869582498.pdfIn PDF document text
    • https://mai-avto.ru/upload_files/file/domujuwogevinunogami.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210908113832.pdfIn PDF document text
    • http://dopuskvsro.ru/UserFiles/bukafonozafanaxawis.pdfIn PDF document text
    • http://damutech.kz/upload/2021/09files/21091310153966853010vyt.pdfIn PDF document text
    • https://impulsa.mantareys.net/uploads/plantillas/files/39647422365.pdfIn PDF document text
    • https://thefertilizerequipment.com/d/files/885027376.pdfIn PDF document text
    • http://timavoshipsupply.it/userfiles/file/sesoxipede.pdfIn PDF document text
    • http://hcbarrett.com/user_area/file/feporajizoxobepibif.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_off0000ccbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCBF 17016 bytes
SHA-256: ffc4d2d8f606e410a12cbdfbfa88e84cda86212a1b729644352b07db7a368baa
font_01_sfnt_off0000f8d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8D8 10028 bytes
SHA-256: 20cd4a9e4d5dadc4ddb2f85a3c95ff840f00ad94dfd470cb26f6ebe98a983414
font_02_sfnt_off00010f01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F01 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1