Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc9e08c85eb2d151…

MALICIOUS

PDF

84.4 KB Created: 2021-07-08 22:25:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9befce96d8ce1603f27decdb7a616f70 SHA-1: ac904b51424a3c8604a05e5d4f1e29d7fa1714cf SHA-256: dc9e08c85eb2d151d7b15223a2f831b7edc1f2ec9b41859408b4cc1774a5189b
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress sites. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest this PDF is part of a link farm designed to redirect users to potentially malicious content. No scripts were extracted, but the primary attack pattern is the distribution of malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • 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://aimhc.com/userfiles/file/nutarixojurewekinilapul.pdf
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cc83e4e95b---90780201208.pdf
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/ou8kpsfsovemghsjrfdmic2f05/33993300866.pdf
    • https://www.electriclighting.com/wp-content/plugins/super-forms/uploads/php/files/89419523132a760d3cdc7cf968e0171d/najazexalowajixuju.pdf
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/uu7qce5ihcehkiuh3g24md0tj3/76593989981.pdf
    • http://www.prieteniitehnicii.ro/documente/file/86001708422.pdf
    • http://changrung.com/ckfinder/userfiles/files/nafajesoj.pdf
    • http://sjar-tech.com/uploadfile/file///2021053117501019.pdf
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a18678b920e---72606670911.pdf
    • http://tpdw.pl/userfiles/file/jirepefitu.pdf
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607b37a86c83e---givepazi.pdf
    • https://kede.org/userfiles/file/padajide.pdf
    • http://provia-events.de/pics/fotos/1/file/xobosenojexa.pdf
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/160d92c667be12---sifimiru.pdf
    • http://matchedtubes.de/userfiles/file/80416490994.pdf
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/120a61c56d59ac1532a8301fad8139f2/waxupogadaduxikojamamas.pdf
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/3c259692153825c6210802870f48a572/21448359302.pdf
    • http://aihyang.com/userfiles/file/tefetiva.pdf
    • http://martom24.pl/martom/userfiles/file/45376208208.pdf
    • http://wksystems.net/HotelEstimator/userfiles/file/garekepilupuzuvaz.pdf
    • https://canvasations.com/wp-content/plugins/super-forms/uploads/php/files/osst1blgl7s8hl3rd3ne8627u2/82985053227.pdf
    • http://businessvaluationapp.com//fck_files/file/tolonorakijosuwijozoxoxir.pdf
    • https://www.waterlooarmsnewforest.co.uk/wp-content/plugins/super-forms/uploads/php/files/d07269bbf19612305a1a51564c37de3b/22228756895.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=funny+small+quotes
    • 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_off0000e7f1.bin
964bf64742ab2b4ebd00ff5bc4eb57f88adf93c67263549e1bfeb3a69cf16899
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7F1 10416 bytes
font_01_sfnt_off0000ff9c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF9C 16792 bytes
font_02_sfnt_off000117ae.bin
1c2a55000777d46dedc85a52c85dd3bc942aee7cb09e8f31a12c1cd9dc2d3335
pdf-font-stream PDF embedded font (sfnt) at offset 0x117AE 17388 bytes