Malicious PDF — malware analysis report

Static analysis result for SHA-256 15b9b4fe78ee32ee…

MALICIOUS

PDF

79.1 KB Created: 2021-09-15 16:10:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 286555ee8e1a03a05a8ee216053456c1 SHA-1: 35ce3ec630ac906a02b1ed20ea85b1262b79f352 SHA-256: 15b9b4fe78ee32ee73d8b066414bd4030baa9c07cb254029e4c134936e639e47
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The presence of numerous embedded URLs, many pointing to PDF files on distinct hosts, suggests a link farm designed to obscure the ultimate malicious destination. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically highlights the use of disposable hosting and UTM term redirectors, reinforcing the phishing or malware distribution nature of the document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://yoron.net/up/files/88499217804.pdf In PDF document text
    • http://quocteanviet.com/img-chamthi/files/vujoroxu.pdfIn PDF document text
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135886d2a1b3---82515753669.pdfIn PDF document text
    • http://www.c-l-r-p.com/admin/ckfinder/userfiles/files/ribisinig.pdfIn PDF document text
    • https://nanyangtextile.com/userfiles/file/tadibidakabiwep.pdfIn PDF document text
    • http://grandfiltr.com/files/file/77388348873.pdfIn PDF document text
    • http://123flower.doweb.kr/upload/files/dapusaxirovu.pdfIn PDF document text
    • https://dolphinsolutions.net/ckfinder/userfiles/files/3166104870.pdfIn PDF document text
    • http://ambulatorioveterinariomariani.it/userfiles/files/1338344124.pdfIn PDF document text
    • http://blueleaves.ru/userfiles/file/538597586.pdfIn PDF document text
    • https://unitedpetexpress.unitedreloth.com/ckfinder/userfiles/files/63346276384.pdfIn PDF document text
    • https://novamakine.com/upload/ckfinder/files/19266873158.pdfIn PDF document text
    • https://jackinthegym.com/uploads/files/202109052030198794.pdfIn PDF document text
    • http://claudiamelchior.it/images/file/kavuvitufotulezux.pdfIn PDF document text
    • https://quizai.com/uploads/files/vakuguwim.pdfIn PDF document text
    • http://t-p-fortune.com/userfiles/file/70852962843.pdfIn PDF document text
    • http://mezon.jp/userfiles/file/labikafuvojab.pdfIn PDF document text
    • https://leciv.fr/uploads/FCK_files/file/22658498614.pdfIn PDF document text
    • http://gilendor.cz/userfiles/file/digewapa.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/e6eabfb1bb2f9879e0f278e5a4af9c4f/92608757615.pdfIn PDF document text
    • http://www.w.radeton.cz/ckfinder/userfiles/files/wixodepafedukavelumonipes.pdfIn PDF document text
    • http://ryukatsu.com/userData/board/file/jarakakejizamuravegiziz.pdfIn PDF document text
    • http://vandofigueiredo.com/userfiles/file///40997669181.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=indian+railway+simulator+download+apkPDF 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_off0000d026.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD026 17644 bytes
SHA-256: f670263d94240a2f4b7f48edd8786dc1c31b3d08a688fd4f7a4e14e3956c6c7b
font_01_sfnt_off0000fde9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDE9 10764 bytes
SHA-256: a9b9b68cc92fee01df45ae717ff05d637f5ab815d4b461a4acb928704957c886
font_02_sfnt_off000116b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116B6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1