Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ca766e6e5bed952…

MALICIOUS

PDF

89.1 KB Created: 2021-07-26 19:11:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8ca6f30aaf26d88928baa7866de75fc5 SHA-1: 7f38bdd4793050a3ecd538455a9ef28af2693156 SHA-256: 4ca766e6e5bed9525d02f4ba6f8d8f805ebe0f4fabc464092d56c651cbe4f63c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF document contains a link farm pointing to numerous distinct hosts, many of which appear to be compromised CMS installations. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple external URIs and a link farm structure suggests an attempt to obscure the ultimate destination and evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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
  • 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 http://wsp.pl/userfiles/file/levubunojev.pdf
    • http://gd-weimi.com/upfolder/e/files/20210705102523.pdf
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/10fn109b0u7u7sn8rh4j4psbvr/nudumomojaxowifogite.pdf
    • https://fentesmakina.com/paket/upload/files/joderukojidafaxebosimid.pdf
    • http://culbertsonlawyer.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dabojuvuli.pdf
    • http://www.anieliasfx.com/uploads/textareas/file/zilumizubegubuvukezi.pdf
    • http://asckhn.com/acskhn/userfiles/file/riligidizomovalarav.pdf
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/a951e41d8a18bb21af7a6398a68adc3c/52195775114.pdf
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/160805834e32b2---toniziwuj.pdf
    • http://botanicgardenscafe.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606ee6d30a830---83751282795.pdf
    • https://bursakaynak.com/userfiles/file/kufukabudifuteperuvolafob.pdf
    • http://expresskaliski.info/file/kifodomezipuwop.pdf
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/daa255a185e54b0f1e6bd0ea3960354d/47418187928.pdf
    • http://mobilephleb.com/clients/2/2d/2d2188d13063160162e6e2bbcdac547d/File/86510659589.pdf
    • https://palcev.ru/userfiles/file/85002709180.pdf
    • http://snypes.nl/img/customer//files/27872362093.pdf
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/0s9ti2mpmkm3rjsaecrnog5hhd/wuzapumawujujo.pdf
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/a6ccc3aab85fb092aadc7830bde117ed/jerarume.pdf
    • https://bahamianbrewery.com/ckfinder/userfiles/files/59937442458.pdf
    • https://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/v2vq31vr709sb8chr6nqurabuq/mobek.pdf
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a2dfe62c627---zobaz.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=leccion+de+escuela+sabatica+en+power+point+por+fustero
    • 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_off0000f20c.bin
689f31907090570d62ec97e412052afe81ac76f7b4a1784cd9b83120711505a1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF20C 10896 bytes
font_01_sfnt_off00010b3e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B3E 16792 bytes
font_02_sfnt_off00012350.bin
68a329a356844f7253f330a5ce82a03f2cb3b5ec0c83b1b46c83c716a44ea72e
pdf-font-stream PDF embedded font (sfnt) at offset 0x12350 19260 bytes