Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef435d67a1328927…

MALICIOUS

PDF

87.5 KB Created: 2021-09-07 00:37:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8b8747ce184d29a181532a8c5a86567f SHA-1: 10a7749c4ca175d40b3ddd7fa657f1fa93038b95 SHA-256: ef435d67a132892733b0cda4bbc936482aef4ebdc663cc1c95ba774b417861b7
164 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 compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • 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://crysiq.ru/uplcv?utm_term=vertu+signature+manual
    • https://austdoorcaocap.com/upload/files/sokujezalamakuwevete.pdf
    • https://primax.fr/wp-content/plugins/super-forms/uploads/php/files/ssbjc4nomjh8ahtfi0tbvn7k41/48865808403.pdf
    • http://airconbank.com/upload/fckeditor/file/60860003146.pdf
    • https://www.groupe-coelho.fr/ckfinder/userfiles/files/fiwudotoxabilefiwuguger.pdf
    • http://borisovhlebprom.by/var/upload/file/22339395292.pdf
    • http://sarlampa.ru/upload_picture/numimupidanunibagabires.pdf
    • https://www.vedaaz.com/wp-content/plugins/super-forms/uploads/php/files/7af9d7184984b6256de695c3ac0cf073/32477481679.pdf
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/1bf383553b7625081997e2b727781864/jonizegipe.pdf
    • http://redwoodpwr.com/wp-content/plugins/super-forms/uploads/php/files/l1m65d7bnhomms85g9iihrqgk0/64716762460.pdf
    • http://allier-genealogie.org/File:/58499521497.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/7b2ef36aa2940ac81b8af62e4f033331/88044854501.pdf
    • http://cuboni.com/uploadfile/hong202108190919006487.pdf
    • http://erainbowrealty.com/userfiles/file/90842455180.pdf
    • http://gonvvama.net/filespath/files/20210907035805.pdf
    • https://www.asahinadigital.com/wp-content/plugins/super-forms/uploads/php/files/v5lq2mqgg9l9fnl3gqbrelc17s/10145063676.pdf
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/543caf1a623d9768e809aa2775127c91/bapagadawimaxiba.pdf
    • http://velapower.com/glwh/UploadFile/file/2021072812414173499.pdf
    • http://healthywithhart.com/res/file/vijekoxirabevawon.pdf
    • http://jshanwoo.com/ckfinder/userfiles/files/namawa.pdf
    • http://www.ernakulamarchdiocese.org/www/js/ckfinder/userfiles/files/30194221634.pdf
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092b53a3d525---88888001133.pdf
    • https://fenicia.uy/fenicia.com.uy/uploads/files/59103248805.pdf
    • http://zuche0551.com/upload/file/11057423935.pdf
    • https://www.techsrollout.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612c4951a2a83---zenemepek.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f245.bin
9f4f33b1a3a8a9f0094f23be5b29e9a00586fc02aa011c9f8363b32486ab84e7
pdf-font-stream PDF embedded font (sfnt) at offset 0xF245 18176 bytes
font_01_sfnt_off000120e4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x120E4 16792 bytes
font_02_sfnt_off000138fb.bin
85735628512889ecfe05da4c9d6df671cf5fbc8650e01d8d662a7a3fad45e904
pdf-font-stream PDF embedded font (sfnt) at offset 0x138FB 10400 bytes