Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9a821025ccd3838…

MALICIOUS

PDF

96.1 KB Created: 2021-07-07 02:18:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c1b0904e07b918d5b0e4b9e2dc5d4645 SHA-1: 1b98568dcac4264a312f6a80765f33f79fa774f8 SHA-256: b9a821025ccd383835582913fa6156ee340063531e7a7e6ee36c2b1bf7c87c56
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1105 Ingress Tool Transfer

The PDF contains embedded JavaScript and multiple external URLs, indicating it is designed to redirect users to potentially malicious websites. The heuristic firings suggest this PDF is part of a link farm hosted on compromised CMS upload directories, likely for phishing or malware distribution. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9946

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://smidgel.ru/uplcv?utm_term=image+to+readable+pdf
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608524585d6e8---wusudelifolu.pdf
    • https://balaji-technology.com/userfiles/file/27515578777.pdf
    • http://lblussana.it/images/file/52597584311.pdf
    • https://www.lamuccacompany.com/wp-content/plugins/super-forms/uploads/php/files/9b34893ed0ec36982c4d32fde6f46335/40374096268.pdf
    • https://marathonlaval.com/userfiles/files/kefafibamidikuximesi.pdf
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/mju2525tbandamfa30tr5l90s3/kozesolixerokujo.pdf
    • http://kadernictvo-svetlana.sk/editor_uploads/system/files/34850148361.pdf
    • http://robertfeinberglaw.com/images/edit_images/file/66502126404.pdf
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/8e6cf4f9bf0f89d44a6cb6ae7c4585b3/54673003313.pdf
    • https://legacyltg.com/wp-content/plugins/super-forms/uploads/php/files/04f4a2f160763ecde28d73c918c9c2bd/41949937616.pdf
    • https://observatoire-omic.org/documents/file/7483152576.pdf
    • https://atlanthealth.com/wp-content/plugins/super-forms/uploads/php/files/b9d7f8084a15b35630e2ed7ffeee6017/60462952768.pdf
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/cc85d3aeb2dce723f1de2791f7688bdc/48358056232.pdf
    • https://utilitydiscount.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b219286b76f---5911177039.pdf
    • http://daieimotors.com/js/upload/files/tejarumuwuboda.pdf
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/160984c0215899---44450871933.pdf
    • https://www.hotwaterfactory.com.au/wp-content/plugins/super-forms/uploads/php/files/04a24da3410a735d73e53f266e856c17/95986314358.pdf
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16086e5d31a1ce---30652773555.pdf
    • https://www.emmabowman.com/wp-content/plugins/super-forms/uploads/php/files/d1d800cfca239a50f72f5a723b9a65ad/tujifajina.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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ec6d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC6D 16792 bytes
font_01_sfnt_off0001047f.bin
fd4eaee662fde99c18d4ab3cf7db0b24763608961444e52c980f2c4aeeed42bb
pdf-font-stream PDF embedded font (sfnt) at offset 0x1047F 19528 bytes
font_02_sfnt_off00013564.bin
0f0283f9fb3353f2e4e0ce18e6f5e5260cef2de306ede7526a346973553c3801
pdf-font-stream PDF embedded font (sfnt) at offset 0x13564 10568 bytes
font_03_sfnt_off00014d07.bin
9785b98fef0050862a817f12d71cd4df34fc191021e2a45f424049bc76bf41af
pdf-font-stream PDF embedded font (sfnt) at offset 0x14D07 2628 bytes
font_04_sfnt_off00015808.bin
f013655eead4ef831ee36de0a827a6a3206d737865cd4690f96dca5fc7977bdc
pdf-font-stream PDF embedded font (sfnt) at offset 0x15808 17548 bytes