Malicious PDF — malware analysis report

Static analysis result for SHA-256 e598c13335fbc5bf…

MALICIOUS

PDF

91.0 KB Created: 2021-07-14 01:11:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 023d7170bc08d41dd76b3c9595933522 SHA-1: 93ed0d1346cbef9307f99d26eff40b20b9bb95ff SHA-256: e598c13335fbc5bf59ec66a5419778c7c1683e6382f668b9e4333d1ffa59273f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious. It contains numerous links pointing to compromised WordPress upload directories and other disposable hosting, suggesting a link farm designed to redirect users. The presence of embedded URLs and the nature of the heuristics indicate a phishing or malware distribution attempt, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://cructi.ru/uplcv?utm_term=how+to+compress+large+pdf+files
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6cf004ad6e---dukojejito.pdf
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160be27bb67467---85211340310.pdf
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/680d46263bfa8928a2071a07e16d1f28/bagagudetusojagesapa.pdf
    • http://scro.ru/pic/file/nutebatiku.pdf
    • https://an-professional.ru/img/files/file/40337961599.pdf
    • http://funkyspa.net/ckfinder/userfiles/files/69370270338.pdf
    • http://brmxn.com/userfiles/file/20210704015517_lytkkt.pdf
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4a1d2d9958---74165996769.pdf
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/6391773cf55408a0f1eb9393c0bda477/47571180344.pdf
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/9c64eab7fa2fce566e0bf1d68a84bfc5/rifirukifovarewusev.pdf
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/j8qj9e58urfbt74tmrk03j5cb7/59963869601.pdf
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160b02f728398d---zalukazuwezirodefetikof.pdf
    • https://nibrasimansch.com/userfiles/files/sijexerilazu.pdf
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/g968civuevl2s4s44b545ks121/70545529707.pdf
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160814fd333bc9---zadobivamijarugomata.pdf
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/jvf0k0ksfjetr6sl302t4bapo4/wubilav.pdf
    • https://trongtrucsolution.com/uploads/files/37586032338.pdf
    • http://amoy-art.com/Upload/file/62628032796.pdf
    • http://angelofthewinds.org/ckfinder/userfiles/files/godubilurigefegojuxujiwog.pdf
    • http://incucinaconalberta.com/userfiles/files/bexinolipegedi.pdf
    • http://eurogeographyjournal.eu/admin/fckfiles/file/99082279946.pdf
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/160b836955cdb5---suzep.pdf
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097c413396cd---48118699249.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_off0000ff89.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF89 16792 bytes
font_01_sfnt_off0001179b.bin
1b54d94b6972d25d91ae04e8745b41c28fada6c5ce727c6d65de3e90efd90642
pdf-font-stream PDF embedded font (sfnt) at offset 0x1179B 17748 bytes
font_02_sfnt_off000145bb.bin
a39e1a41d621b8f86db284976e8ac406f942988c97f90f7b18a44c4c07c6ffa0
pdf-font-stream PDF embedded font (sfnt) at offset 0x145BB 10936 bytes