Malicious PDF — malware analysis report

Static analysis result for SHA-256 5559df598ea47389…

MALICIOUS

PDF

78.5 KB Created: 2021-09-11 00:22:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1be6c452bee4ab8fc06689bcbdeee195 SHA-1: 140259dc8a7666c77dbe71b9a09e78e3408327e9 SHA-256: 5559df598ea47389331be691bcff2b06238959a8592f3f3a702a97900da301b4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that form a link farm, directing users to various domains, some of which are hosted on compromised CMS platforms. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://chcial.ru/uplcv?utm_term=how+to+access+the+root+on+android PDF link annotation
    • https://giaynangchieucao.com/userfiles/file/34657994685.pdfIn PDF document text
    • http://yjbiotech.cn/upload/files/34588854617.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613625e314f2b---5489607927.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/786fcc6454c06acfc01f16d33c052ff3/35861439540.pdfIn PDF document text
    • http://iweldbot.com/ckfinder/pho/files/86477737877.pdfIn PDF document text
    • http://kondicionery-shodnya.ru/upload_picture/file/zajewadirok.pdfIn PDF document text
    • http://ustunongel.com/image/files/79813642778.pdfIn PDF document text
    • https://tekartltd.com/upload/files/pexoselotowemigizovowegi.pdfIn PDF document text
    • https://ms01bet.com/contents/files/valab.pdfIn PDF document text
    • http://dolphinegypt.net/userfiles/file/25145970609.pdfIn PDF document text
    • https://ddtoyz.com/ckfinder/userfiles/files/kabuvaw.pdfIn PDF document text
    • http://sinhorelli.com/userfiles/file/wefofot.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132f5ea95144---79154255875.pdfIn PDF document text
    • http://erex.hu/upload/file/5775884903.pdfIn PDF document text
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/4l1ijtdhh6l7vak8ojlltnsgrj/55518254248.pdfIn PDF document text
    • http://nhatrangpalace.vn/app/webroot/upload/files/ruvunifekisijefoze.pdfIn PDF document text
    • http://nicenpos.com/userData/board/file/pifaruvuji.pdfIn PDF document text
    • http://hondatayho.vn/images/ckeditor/files/refalosolopadafesufo.pdfIn PDF document text
    • http://www.ondebiz.com/userfiles/file/zonisinajevakimajew.pdfIn PDF document text
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/5bf60c443bf5438a2ab0071265ca9f26/sapiriruwuradazikoko.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16133c2d553991---66750701207.pdfIn PDF document text
    • http://kosmonautika.ee/ckfinder/userfiles/files/moxijepinebagasaxuja.pdfIn PDF document text
    • https://wspaperbag.com/userfiles/file/2082499046.pdfIn PDF document text
    • https://geelaboba.dswip.com/ci/userfiles/files/83512622021.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_off0000caab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAAB 19252 bytes
SHA-256: 504c0411857023381e9d9e147171f0c36fa1f0ab0c42b90219689a4262c0c625
font_01_sfnt_off0000fc01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC01 10496 bytes
SHA-256: 67ffeab3545d937e236650005d241346128d734279fa3386bc6fadd15670389b
font_02_sfnt_off000113de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113DE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1