Malicious PDF — malware analysis report

Static analysis result for SHA-256 b631bd645438ecd0…

MALICIOUS

PDF

246.6 KB Created: 2021-07-18 23:16:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 6e78aee67d31bcb9197529d3fdf86920 SHA-1: 18a056ccdae1aff29d6114f48047e0371eb1edf8 SHA-256: b631bd645438ecd0eecf0eed05615a7245ebc246fccf17641b5fece9767f8c02
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple links to external resources, with several pointing to compromised WordPress sites hosting PDF files. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to deliver a second-stage payload. The presence of PDF_RANDOM_URL_LINK and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, suggesting an attempt to host malware on vulnerable CMS platforms.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9766

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • 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://maslag.eu/userfiles/file/72221381574.pdf In PDF document text
    • http://rotarylaspalmas.org/documentos/file/javikekunib.pdfIn PDF document text
    • http://servmed.net/userfiles/file/razizus.pdfIn PDF document text
    • http://textingrights.com/userfiles/files/bovuxegajusobugazuzipumo.pdfIn PDF document text
    • https://www.vedaaz.com/wp-content/plugins/super-forms/uploads/php/files/4aec3348422e4a22d1dba3819afd70b8/lowexomowegegivur.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b552b151a0---fiwataribipomebepeve.pdfIn PDF document text
    • https://eric-parnes.com/ckfinder/userfiles/files/14503958052.pdfIn PDF document text
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/38b2c743885acc2b88f7a4b0f4e4c105/22694638792.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/160822f6f03dc3---77711062106.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079c5c1c0d68---95483902108.pdfIn PDF document text
    • https://canvasations.com/wp-content/plugins/super-forms/uploads/php/files/jptss29uavo6jlma4g7r6bteo7/vizemuzipesitefabuv.pdfIn PDF document text
    • https://its-bulgaria.bg/files/file/98578661508.pdfIn PDF document text
    • https://daluxerealty.com/wp-content/plugins/super-forms/uploads/php/files/ostc4rrp65gtksmfll354c28u7/jesumozekugokulov.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/nmmkn57mcq24q7vr35mjskji41/93373856781.pdfIn PDF document text
    • https://jagamimpi.org/contents//files/fanabijawujadesida.pdfIn PDF document text
    • https://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/c968c2c63407ba6cc7b664b199c98a44/9663920586.pdfIn PDF document text
    • http://zhxndl.com/uploadfiles/files/66803542465.pdfIn PDF document text
    • https://wecareprogram.org/images/file/tomomavorategetodotejad.pdfIn PDF document text
    • http://omg.su/upload/File/19509687285.pdfIn PDF document text
    • http://saintthomasmonrovia.org/clients/a/a7/a774d5b45fc75aba9c6fcf07501e1e58/File/govajixoluvimalolevuseg.pdfIn PDF document text
    • http://noxsun.com/jingkelun/userfiles/files/20210616045720.pdfIn PDF document text
    • http://doctour.hu/uploads/ckfinder/userfiles/files/71176777643.pdfIn PDF document text
    • https://mariellatriolo.it/public/file/binototujamijemapi.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/ldc8oo0uu4d1fhgild9snbusr5/jebuturotof.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1607d236237e6a---97336588090.pdfIn PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/160c0e48f410da---pelenazajobas.pdfIn PDF document text
    • http://booklandbooks.com/userfiles/file/padekatiga.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=griffiths+intro+to+electrodynamics+solutionsPDF 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_off000365b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x365B4 10992 bytes
SHA-256: 6007f9b2514c9a0d00577b7fb66f439e9e3da053d1d63550bdb75bb36d427a20
font_01_sfnt_off00037f20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x37F20 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00039732.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x39732 19524 bytes
SHA-256: 710e9901d3b75146f9173aff127941205777e860e24ab44cd43896ef9485624e