Malicious PDF — malware analysis report

Static analysis result for SHA-256 848f7f0b2b5ffcbf…

MALICIOUS

PDF

72.3 KB Created: 2021-09-28 03:45:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 953e884902a6aa4b974709f0c1aa1694 SHA-1: 47cea5c339e530a5a67ee1e54ddb942f4b80e6d6 SHA-256: 848f7f0b2b5ffcbf77e0d79176d4c099d73b080a78616bfb1938cc5ebae842f4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories, suggesting a phishing or redirection scheme. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to malicious sites or download further payloads. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 6

  • 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.
  • 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://ketchas.ru/uplcv?utm_term=4k+dynamic+wallpaper+mac
    • https://bmw-zona.ru/uploads/file/peweniduzedojemu.pdf
    • https://jv-cms.crazy-jessie.nl/uploads/files/12810270521.pdf
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613e9bfaa7f1a---jegajibi.pdf
    • http://hanhthien.net/uploads/file/dujijizawuwidatuxagij.pdf
    • https://vos-web.nl/userfiles/file/xuzovewudabijuzital.pdf
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/16139d60573e3a---12662625876.pdf
    • http://ticaproduce.com/ckfinder/userfiles/files/vafiv.pdf
    • http://panyuchen.com/ckfinder/userfiles/site_eachfun_com/files/45142865426.pdf
    • http://superbarter.sk/media/file/tamugogexerazolaji.pdf
    • https://fundacionamigosdelmarcaribe.ong/ckfinder/userfiles/files/3056497532.pdf
    • https://ptogel1.com/contents/files/97626847562.pdf
    • http://biosafety.biz/ckfinder/userfiles/files/94730659906.pdf
    • http://www.ecostroyservis.ru/File/36913472598.pdf
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/11a9a8502e5889814f43ed426cf4eb95/66474794141.pdf
    • http://vom-ragnaroek.de/uploads/file/mepizuvutu.pdf
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614137a904ffc---mibajonadizeninunu.pdf
    • http://autoset66.ru/admin/ckfinder/userfiles/files/52143284837.pdf
    • http://deborahmayerlawoffices.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nusoratakiborikedili.pdf
    • https://associazionedynamica.it/uploads/file/37319657547.pdf
    • http://highspiritsmusic.com/ckfinder/userfiles/files/zimipesovulejofuripaf.pdf
    • https://vivaldiroberto.com/img/files/mediafiles/file/20717200464.pdf
    • http://educaholistica.com/resources/img/imagesck/files/kidixexino.pdf
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/3n2sd66d0c4clnh8m7inb088p8/73715398794.pdf
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613f59cfa4492---guwowutobotufuluxulu.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_off0000b36e.bin
577e52b52709148a2436032b763606d69bd1aad2073c009d487e5653265afd4a
pdf-font-stream PDF embedded font (sfnt) at offset 0xB36E 18148 bytes
font_01_sfnt_off0000e1ff.bin
6e27e7e453bb473d52bfaf61c33dffdb12a12d96ce1935b01be176ae7319c7f6
pdf-font-stream PDF embedded font (sfnt) at offset 0xE1FF 10564 bytes
font_02_sfnt_off0000fa16.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA16 16792 bytes