Malicious PDF — malware analysis report

Static analysis result for SHA-256 a824103b8ad358fd…

MALICIOUS

PDF

74.8 KB Created: 2021-09-20 18:54:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 866537257fb6bc242adfdc36c2651d39 SHA-1: cad49b7165ffb2d038918bcad98c6a3df71c3ecf SHA-256: a824103b8ad358fd9c15f2e69976fcb5c8db73d506654a0c6b258e67e2c063f3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The PDF structure and embedded links are consistent with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://queure.ru/uplcv?utm_term=valores+del+desarrollo+organizacional+pdf PDF link annotation
    • http://autoscuolepintozzi.it/userfiles/files/wowilariber.pdfIn PDF document text
    • http://hindustanadvancedsolution.com/t/tutorfirm/uploads/ck/files/kodigotevifuwakererujove.pdfIn PDF document text
    • https://sydneystudytour.com/accounting/userfiles/file/naxuxi.pdfIn PDF document text
    • https://danfort.lv/userfiles/file/46702721041.pdfIn PDF document text
    • http://standdominica.org/files/files/xuzurixifukomafijaz.pdfIn PDF document text
    • http://abwlargo.com/uploads/files/liluda.pdfIn PDF document text
    • http://www.dogwoodagility.nl/ckfinder/userfiles/files/7683542204.pdfIn PDF document text
    • https://economiadecomunion.net/ckfinder/userfiles/files/96139677280.pdfIn PDF document text
    • http://tuanayapim.com/rsm/files/43496402810.pdfIn PDF document text
    • https://krainaogrodow.eu/zdjecia/fck/file/xidewatifabowov.pdfIn PDF document text
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/b1dfc0cd71be9b83bb3fcdce36685e84/5430023333.pdfIn PDF document text
    • http://denis-lefebvre-services.com/fichiers/file/lelakunogarezowu.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613ea555329f5---fivopupikipifizapojopa.pdfIn PDF document text
    • http://sherwoodonionfestival.com/ckfinder/userfiles/files/61444730070.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/80aa06b8390f04690b7a002ae390ea0c/85862213817.pdfIn PDF document text
    • http://tlumacz-lipno.pl/pdrzewiecki/files/nuroxinewularogu.pdfIn PDF document text
    • https://natyabio.com/uploadfiles/5037029534.pdfIn PDF document text
    • https://n-vv.dk/userfiles/file/tedarufezoruzulujomixave.pdfIn PDF document text
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/303f63973716aa143c8805372957f780/73572311761.pdfIn PDF document text
    • http://insfilings.com/skyzone_classic/upload/files/88433783380.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b4bfa57f39---56538616554.pdfIn PDF document text
    • https://mariapolis.net/ckfinder/userfiles/files/gozaje.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_off0000c2ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2EC 16936 bytes
SHA-256: b6dd9c944ae4e15b062db0d8153e74147a9adacd478ddc81503ea390861dc490
font_01_sfnt_off0000ed4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED4F 10724 bytes
SHA-256: 8dc705e81f457b30708c4fc1ef6377ffbe0cebdb5cefe6d70a44f76c53770b94
font_02_sfnt_off000105d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105D9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1