Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4a97d1ed6ebaec0…

MALICIOUS

PDF

69.6 KB Created: 2021-10-02 22:28:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: fe31cf80f99a421d542d0276dbac7bed SHA-1: b5dd492df7e2c918a3f5ad443af6dfb6cda7b092 SHA-256: a4a97d1ed6ebaec006011645a090c9304c81ebc5ded7f3262cbc36ff596bf72a
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document flagged by multiple heuristics as malicious, including a high-severity PDF_RANDOM_URL_LINK and ML_NYX_PDF_MALICIOUS. It contains a large number of external links, many pointing to domains that appear to be part of a link farm, suggesting a phishing or malware distribution campaign. The ClamAV detection further confirms its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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 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.
  • 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://catamma.ru/uplcv?utm_term=what+are+the+disadvantages+of+biometrics PDF link annotation
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/d04fca90944b661c6d749e13b52aa67a/masizamipaleg.pdfIn PDF document text
    • https://ambulatorioveterinariosismondi.eu/file/dafovititidopiluwana.pdfIn PDF document text
    • https://possamaiferramenta.it/uploads/file/99252341806.pdfIn PDF document text
    • http://dydlhx.com/upfiles/file///falel.pdfIn PDF document text
    • http://www.themixchange.com/userfiles/files/22444973412.pdfIn PDF document text
    • http://coreaad.com/DreamDataUpload/file/10323915993.pdfIn PDF document text
    • https://manajrgvaaradhi.com/cms-uploads/files/vumizu.pdfIn PDF document text
    • http://braghieriarchitettura.com/userfiles/files/37230518276.pdfIn PDF document text
    • http://tupnate.com/ckfinder/userfiles/files/jusuzakurogedidimidaran.pdfIn PDF document text
    • http://kes.org/upload/editor/files/33702240611.pdfIn PDF document text
    • http://resortcrimea.com/ckfinder/userfiles/files/dotezoniwibipozulurag.pdfIn PDF document text
    • https://rzfmuhasebe.com/userfiles/file/bejufofimojibevikovo.pdfIn PDF document text
    • https://rosebankprimary.co.za/inc/ckfinder/userfiles/files/pukufamaxasej.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/9eccd40a6bbead41b26e63de7a77f93b/26802538678.pdfIn PDF document text
    • http://thuaphatlailongthanh.com/upload/contentFile/minhchau/file/70241527068.pdfIn PDF document text
    • https://www.cosanuesa.com/componentes/editor/ckfinder/userfiles/files/mewolusofunujemotumerena.pdfIn PDF document text
    • http://zapatosperezcabrera.com/ckfinder/userfiles/files/kefikakaluzoregife.pdfIn PDF document text
    • https://pro-biomed.com/admin/userfiles/file/fudojetux.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_off0000abbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xABBC 17168 bytes
SHA-256: 50cd52f405a346c74ddc6c1b73e53b8da3d66e6b3f83efab010e491fb0349bb1
font_01_sfnt_off0000d77e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD77E 11076 bytes
SHA-256: 313a658a9ad3a53e518a3d4e825375f703e5d127c77971bb422386ea39066dde
font_02_sfnt_off0000f0fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0FA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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