Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb76d5e48d3d8114…

MALICIOUS

PDF

87.8 KB Created: 2021-07-31 05:10:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 599a1efe9494e5fc4a842ae1d01966fd SHA-1: 3039c73d9a97102dd3a6d81bcaf9eeeba9668ce3 SHA-256: cb76d5e48d3d81149801844c7605a005e16e9f1377bce69b43682eb40f012720
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised CMS upload directories, indicating a link farm designed to host or distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, and the document body was unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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 https://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/33e3762437989e64e3e4e3fdf6468186/61574844186.pdf
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a5186b02fdb---27188107628.pdf
    • http://mamsn.com/upload/miwunuzivomupaz.pdf
    • http://niezapominajkowo.eu/userfiles/file/betekidivokemisemefuwo.pdf
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/k4nqk4u2i5los5j29m263urf83/bokijijemipomijupafuma.pdf
    • https://canadiancontractorservices.com/wp-content/plugins/super-forms/uploads/php/files/jrg5tlln2599e8d894knela3l5/44501616231.pdf
    • https://bustotoronto.com/userfiles/file/zefovaredufo.pdf
    • http://capital96.com/userfiles/file/71803538718.pdf
    • https://augsburger-dartliga.de/uploads/file/20785909296.pdf
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be8c82ccf97---sabez.pdf
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160e4c9a160cc9---gijeratazarazi.pdf
    • http://gld-lining.com/user_img/files/mepaxupoxezuzebu.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f9eee6d0b2a---filizaketusapilaj.pdf
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160d51b0320d0e---vamukinenirudan.pdf
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/132cbe07bc49cefb82f279bedfa21ef9/90291193015.pdf
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160ee1997717e3---funupufebejikenekip.pdf
    • https://dmddsgn.com/wp-content/plugins/super-forms/uploads/php/files/8eb445ba30318739e43268e41d4ad466/viwimidegixefipozusa.pdf
    • http://megat.pl/uploaded/fck_files/file/90435544675.pdf
    • http://www.verneteco.com/ckfinder/userfiles/files/xelewirimevadem.pdf
    • http://lideparts.com/userfiles/file/1621617255.pdf
    • https://www.waterlooarmsnewforest.co.uk/wp-content/plugins/super-forms/uploads/php/files/39247445845a66da2271d004d362cf15/40872521319.pdf
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e6c375236e3---11670873092.pdf
    • http://marcelponjee.nl/ponjeefiles/file/15471335813.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=basic+civil+engineering+drawing+book+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_off0000f2dd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2DD 16792 bytes
font_01_sfnt_off00010aef.bin
82fd2f8ec57efb8e2b04efcbf823b6f62691e3ce0dd5cfe972044a6b205b3d39
pdf-font-stream PDF embedded font (sfnt) at offset 0x10AEF 16256 bytes
font_02_sfnt_off0001350e.bin
6962e5cef0d374ae99608d56fdcf7c05804820516bcc215ea7c5e1d856b69e05
pdf-font-stream PDF embedded font (sfnt) at offset 0x1350E 11136 bytes