Malicious PDF — malware analysis report

Static analysis result for SHA-256 13f26f385000da41…

MALICIOUS

PDF

81.5 KB Created: 2021-09-20 00:25:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: b245464b4e5ecd68fe76f847e50d98c8 SHA-1: 0b161ac673d87e1015a85fff62d7c1db3788fa44 SHA-256: 13f26f385000da41be4c0c68781a6e15a3fa983081a57740e139193c0934e587
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for delivering malicious payloads. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of numerous unknown URLs suggests a phishing or malware distribution campaign, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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
  • 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.
  • 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://habrit.tw/ckfinder/userfiles/files/toloposiniwis.pdf In PDF document text
    • https://lotusmarinevn.com/upload/files/38828596450.pdfIn PDF document text
    • http://lesmashclub.com/imgUpload/files/texosoxujilepamurofo.pdfIn PDF document text
    • http://varadimasszazs.hu/uploads/files/vilagiwivusuxedekotajev.pdfIn PDF document text
    • https://artbynela.com/uploads/file/vigesix.pdfIn PDF document text
    • https://sankaibearing.com/userfiles/files/38576644213.pdfIn PDF document text
    • http://hocikto.info/userfiles/file/dubevazi.pdfIn PDF document text
    • http://antropolog.ru/userfiles/file/padilorajuxujoriv.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/16140cb737d374---xuzebudabefixupexuraxok.pdfIn PDF document text
    • http://www.llmhospital.com/www/js/ckfinder/userfiles/files/miwolelisof.pdfIn PDF document text
    • https://griby.biz/ckfinder/userfiles/files/71791966617.pdfIn PDF document text
    • https://www.displaysdirectaustralia.com.au/application/third_party/ckfinder/userfiles/files/nijazitogelujabigakewure.pdfIn PDF document text
    • http://videlec.be/ressource/file/wukabe.pdfIn PDF document text
    • http://weingut-suppan.at/files/kufolepuzeki.pdfIn PDF document text
    • http://test-immo.com/file/xasorapuna.pdfIn PDF document text
    • http://air-ned.com/uploads/files/junixux.pdfIn PDF document text
    • http://craftland.de/res/wysiwyg/file/4859787362.pdfIn PDF document text
    • http://svx.su/ffile/file/2687445832.pdfIn PDF document text
    • http://shriadinathbank.com/uploads/tumefa.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/64275384464.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16135846febaf3---33008976787.pdfIn PDF document text
    • http://studiolegalezullo.eu/userfiles/files/46503275893.pdfIn PDF document text
    • http://como.gattinonimondodivacanze.it/themes/userfiles/files/sufogojikixemikazifupop.pdfIn PDF document text
    • https://www.confirmedtour.com/files/10237557264.pdfIn PDF document text
    • https://nirmalujjwal.com/public/ckfinder/userfiles/files/vavepusonewipikejarawovep.pdfIn PDF document text
    • https://duongthuy.net/userfiles/file/28884882122.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=can+i+use+my+phone+as+a+nfc+tagPDF 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_off0000d99b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD99B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f1b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1B2 11028 bytes
SHA-256: 80d8eb25d7dcb9dc4146e08da591619cc6e9df3265632cf5f5960ae8346abaf0
font_02_sfnt_off00010b41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B41 17352 bytes
SHA-256: 52972547bf660a344132d701f9c034b012acbeb272f8c719803ec8a33911f785