Malicious PDF — malware analysis report

Static analysis result for SHA-256 f33c4156c1dde387…

MALICIOUS

PDF

87.4 KB Created: 2021-09-12 14:03:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-07
MD5: 4ffd152a88e9594406f748157f84180f SHA-1: a37305e35140313f35165e5096cfad01865e0d6d SHA-256: f33c4156c1dde387522ed9c66f619b757ad34fb8caa58b0d093096729a854391
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to disposable domains and are structured as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to trick users into downloading further malware. The presence of embedded JavaScript suggests an attempt to execute malicious code upon opening or interaction.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://medvor.ru/uplcv?utm_term=best+chess+game+in+android PDF link annotation
    • http://stnicholasway.com/userfiles/file/zoluti.pdfIn PDF document text
    • https://kalitelivideoizle.com/resimler/files/27986365899.pdfIn PDF document text
    • https://congchung7.com/upload/file/28011585287.pdfIn PDF document text
    • http://pumarecovery.com/userfiles/files/jedapavepejalafuboneku.pdfIn PDF document text
    • http://quimis.org/js/ckfinder/userfiles/files/tulomupizunepogo.pdfIn PDF document text
    • http://kfnmsz.com/upfolder/e/files/20210902135201.pdfIn PDF document text
    • https://fiscconsulting.com/userfiles/file/pirezopi.pdfIn PDF document text
    • http://www.cenlajobinator.com/siteuploads/editorimg/file/9588176758.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613913a480af6---budeguwanasuxiwuranu.pdfIn PDF document text
    • https://maintogelonline2.com/contents/files/zuxiluk.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613704993bbe7---92944437189.pdfIn PDF document text
    • https://arvikabc.com/images/uploadedimages/file/fotarigubifawubirofaro.pdfIn PDF document text
    • https://botroul.be/uploads/64265648263.pdfIn PDF document text
    • https://ksboutlet.com/file/files/jutubulejobepebibujife.pdfIn PDF document text
    • https://wodepcb.cn/uploadfiles/files/rovukilejetafef.pdfIn PDF document text
    • http://kleinschadenexperte.de/userfiles/file/32378210430.pdfIn PDF document text
    • http://jump360.co/upload/files/20210910054742.pdfIn PDF document text
    • http://garageanything.com/js/upload/files/vibajaxigutiserinibera.pdfIn PDF document text
    • http://travelshops.pl/userfiles/file/74349418939.pdfIn PDF document text
    • http://theffirm.com/userfiles/file/tazusijiv.pdfIn PDF document text
    • https://fiscconsulting.com/userfiles/file/17103869220.pdfIn PDF document text
    • https://tjpapigroup3.com/contents/files/24293119350.pdfIn PDF document text
    • http://irs-messtechnik.at/upload/zijurozaved.pdfIn PDF document text
    • https://dudikom.pl/userfiles/file/40638420800.pdfIn PDF document text
    • http://inica.org/files/file///fawuwitibilolodikubuxager.pdfIn PDF document text
    • http://ux-school.ru/files/files/furazulewesevat.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_off0000ef31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF31 10824 bytes
SHA-256: 805ae8088b4230c52f2591ab609f53a5dc481db78e70054180caf835c654ba1b
font_01_sfnt_off000107cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107CC 18328 bytes
SHA-256: 6a05529dfcc98e0333be413ad329219479e4c72953fdf503a3f3fd686a054119
font_02_sfnt_off0001376a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1376A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1