Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ec9fbeb4a4c2b2a…

MALICIOUS

PDF

71.8 KB Created: 2021-09-19 14:59:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fb37646ecb003d9f67097ee137b23f9e SHA-1: a5ea4312208b883c0be8e3bf25e296a50c0da9b5 SHA-256: 4ec9fbeb4a4c2b2a20eb377706f51a74eb2545d61ca7715204f5d97ad2b0ef2d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external URIs, many of which point to compromised WordPress uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution through these links. The embedded JavaScript is likely responsible for redirecting users or initiating further malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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
  • 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://oniceh.ru/uplcv?utm_term=cleveland+browns+wallpaper+for+android
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614455d68133e---74876566.pdf
    • http://zs-g.jp/app/webroot/js/ckfinder/userfiles/files/54217028364.pdf
    • http://mkbeauty.vn/luutru/files/13568675473.pdf
    • http://smolninskayahotel.com/userfiles/file/katepekawuku.pdf
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/66d924e08ac4c2172acd3140421fa7a2/limilo.pdf
    • http://recrute.fr/files/files/gagosedata.pdf
    • https://rintrans.com/files/48614471854.pdf
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/8c061d190c85e704b85711b8fcd85479/xigozowuxudumepa.pdf
    • http://blesk-stroy.ru/userfiles/files/simenafigipuwas.pdf
    • http://patrick-vallot.com/upload/files/14645999722.pdf
    • http://methese.com/upload/files/lamafipuxadukenuvoragaze.pdf
    • http://dream-mebel.com/pic/file/feseritazefufebujeza.pdf
    • http://fiumevivo.it/userfiles/files/41336897766.pdf
    • http://winecellarkeeper.com/ckfinder/userfiles/files/pewununekerilunutameli.pdf
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/7432f0e0bfb0f945e6f70c63b51df1a2/61469632236.pdf
    • http://minhanh.com/files/28915924832.pdf
    • http://alatasfilms.gr/ILC/img/file/51334587136.pdf
    • https://lotteppta.net/beta/assets/file/24422593102.pdf
    • https://najlepsze-w-polsce.pl/uploads/1866331160.pdf
    • http://sergeisurzhin.ru/ckfinder/userfiles/files/gumumano.pdf
    • https://transmar.biz/ckfinder/userfiles/files/rukev.pdf
    • https://dianthusindustrial.com/resimler/files/mamixowidezawulixepafi.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_off0000b7f2.bin
9ac3e2b1e5c7053b4b4f593c46ac805c08f34c07e68e1e973c05ee9c5fb08b47
pdf-font-stream PDF embedded font (sfnt) at offset 0xB7F2 15876 bytes
font_01_sfnt_off0000e0b9.bin
71e28b9aa4742993d8c024adf11898047082b8250762c6183705ed7771eaa6d5
pdf-font-stream PDF embedded font (sfnt) at offset 0xE0B9 10716 bytes
font_02_sfnt_off0000f946.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF946 16792 bytes