Malicious PDF — malware analysis report

Static analysis result for SHA-256 43b36005f138c1d2…

MALICIOUS

PDF

80.5 KB Created: 2021-09-07 03:45:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 9865051e3a11144577d24f627fddc4ca SHA-1: f799203f4e2daa6de9ad99001a42f3b2b96f283e SHA-256: 43b36005f138c1d2b528091ff5d937010280289962c8508ddeaa7aa82add87c1
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised WordPress upload directories and other disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The document body is heavily obfuscated and unreadable, providing no direct content-based lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://cructi.ru/uplcv?utm_term=browns+2019+schedule+pdf PDF link annotation
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c2de0b0621f---24394987444.pdfIn PDF document text
    • http://tw-jia.com/uploads/files/202109021034098694.pdfIn PDF document text
    • https://raiporjai.com/piceditor/file/xisijax.pdfIn PDF document text
    • https://bocion.com/ckfinder/userfiles/files/kevawinawanotipopufukoso.pdfIn PDF document text
    • http://asdgolfclubtoscana.com/writable/public/userfiles/file/vuneluwutonuxenetisu.pdfIn PDF document text
    • http://musicpark-live.de/userfiles/file/tanenuna.pdfIn PDF document text
    • https://urbanshapes.in/userfiles/file/sijikagidepexigowod.pdfIn PDF document text
    • http://nkland.org/userfiles/files/katud.pdfIn PDF document text
    • https://lasanisports.com/files/7972099392.pdfIn PDF document text
    • http://biznesfishki.ru/files/userfiles/files/xulom.pdfIn PDF document text
    • https://tipresentoio.it/images/file/vipew.pdfIn PDF document text
    • http://www.fonfe.com/uploads/files/54046557946.pdfIn PDF document text
    • http://davidhammerstein.org/userfiles/file/febuzul.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-6-20/20210620112131538941.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160e170a32a645---momenamedimopid.pdfIn PDF document text
    • https://global-brand.net/userfiles/files/47018807658.pdfIn PDF document text
    • https://gbeequestriansurfaces.com/wp-content/plugins/super-forms/uploads/php/files/gcmiljndu2ct78jnua5fserokr/bakiwalumu.pdfIn PDF document text
    • http://denki-shonan.com/uploadsfile/pudowitudiluda.pdfIn PDF document text
    • http://timnhanhonline.vn/upload/files/dokuburivigopurodufuz.pdfIn PDF document text
    • https://www.phuketvillarentalandservices.com/ckfinder/userfiles/files/14424160337.pdfIn PDF document text
    • https://borgopitti.it/userfiles/file/6802738274.pdfIn PDF document text
    • https://network-italia.it/file/36245272361.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_off0000d74b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD74B 16712 bytes
SHA-256: 136831beabb3cec7bafbe89dfa2c0aa41f2f857b60eafcf17199d2eef0b54034
font_01_sfnt_off000102d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102D5 11068 bytes
SHA-256: a6d737ef3547bac82f03c6358db51b03161dfd50f6cff56f3911a5f333348491
font_02_sfnt_off00011cb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1