Malicious PDF — malware analysis report

Static analysis result for SHA-256 43a754ae25c3edf3…

MALICIOUS

PDF

112.9 KB Created: 2021-10-19 11:35:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 379eab3814f5ac97dba3762f3b7ac6af SHA-1: 65bc4a188d44074a7559e115f652c3e49e385ca7 SHA-256: 43a754ae25c3edf33701d1c03cf199d067dd046487dc0594a23db28745087253
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs and is flagged by heuristics as a link farm on disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded links are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://kbinteriery.cz/userfiles/file/54954463604.pdf In PDF document text
    • http://doremimarlikinsaat.com/userfiles/file/90788120635.pdfIn PDF document text
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/powumuwafogokakuzamux.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615eb3e7b75bb---faximerivisovawapatu.pdfIn PDF document text
    • https://eatorhours.org/e-bussiness/fckimages/file/silabitudabegilaxikodep.pdfIn PDF document text
    • https://oasis-travel.ro/files/gosekuxale.pdfIn PDF document text
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/fokon.pdfIn PDF document text
    • http://4rrecycle.com/files/file/36788783273.pdfIn PDF document text
    • http://studioguagnoni.it/userfiles/files/3295426401.pdfIn PDF document text
    • http://krallarintavugu.com/upload/file/boturofu.pdfIn PDF document text
    • http://labradory.pl/file/69714544689.pdfIn PDF document text
    • https://alirezamirmohammadi.com/images/upload/files/gurarosidazuw.pdfIn PDF document text
    • http://acrclubinversores.com/files/galeria/files/60561963025.pdfIn PDF document text
    • http://yomamasushitogo.com/uploads/files/fevirinasawixofatedamesoz.pdfIn PDF document text
    • http://studioferrato.it/userfiles/files/sovugewatunorol.pdfIn PDF document text
    • http://tienhasteel.com/app/webroot/upload/files/93867106882.pdfIn PDF document text
    • https://oasis-travel.ro/files/jonunaxamiwasase.pdfIn PDF document text
    • https://mlbcsimleague.com/ckfinder/userfiles/files/85572216527.pdfIn PDF document text
    • https://palet-school.com/files/files/dopanoladut.pdfIn PDF document text
    • https://mygrind.ie/userfiles/file/14127427797.pdfIn PDF document text
    • http://www.drivingschool-brno.cz/files/files/80158659959.pdfIn PDF document text
    • http://quangphong.vn/uploads/image/files/81500784088.pdfIn PDF document text
    • http://e5tbr2.alruaa.com/ckeditor-ckfinder-integration/uploads/files/46353345515.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/2I9n2o-U8HI/uplcv?utm_term=beck+depression+inventory+2+onlinePDF 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_off00014fe4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14FE4 19944 bytes
SHA-256: f5a6458cae09febe6e674e0d0455b6f0dc174872c3723a201d5c0b42d732630a
font_01_sfnt_off0001847b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1847B 10792 bytes
SHA-256: 2f295090aabd281245b0558025df3ce5be7d0d5d3c119cd1dd889b9dc6d252eb
font_02_sfnt_off00019d8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19D8D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1