Malicious PDF — malware analysis report

Static analysis result for SHA-256 28d8611f5daf4376…

MALICIOUS

PDF

78.1 KB Created: 2021-08-29 16:28:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fa1b991f9edcffa4c119c5c8e34c25cb SHA-1: 7dc3a8f3733f4cfaa9e43803aa9608f029623425 SHA-256: 28d8611f5daf43768cc886b2d87c12bb08485b2db0fab933986db2d349111305
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised websites and disposable hosting domains. The presence of numerous external URIs and link farm indicators suggests the primary goal is to redirect users to potentially malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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://crysiq.ru/uplcv?utm_term=new+vocaloid+songs
    • http://neoneophytou.com/ckfinder/userfiles/files/27373631441.pdf
    • https://jollytime.ru/wp-content/plugins/super-forms/uploads/php/files/6934b200dd9ab42110dfc134dc6f5cee/30643918206.pdf
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16107dafc37a5f---ratodadunalolafoxowada.pdf
    • http://ajtoablakcentrum.com/_user/file/52658625534.pdf
    • http://career-id.org/ckfinder/userfiles/files/fixeredaxokinolidovetugeg.pdf
    • http://austria-ex.com/images/blog//file/debututoxam.pdf
    • https://oncetrabzon.com/resimler/files/41063884785.pdf
    • http://e3edu.vn/public/ckfinder/core/connector/php/connector.phppublic/uploadsfiles/fenovibeki.pdf
    • http://ogcdc.org/uploads/ck_upload/files/31905454333.pdf
    • https://colegiumaniucarei.ro/ckfinder/userfiles/files/buzukaripuzol.pdf
    • http://salonorganica.ru/upload/files/66204222493.pdf
    • https://moolans.com/uploads/files/37809986233.pdf
    • http://sntaviator.ru/ckfinder/userfiles/files/vetufefufununike.pdf
    • http://korealabels.com/ckfinder/userfiles/files/1718375957.pdf
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/1606f0cfb58b9b---88074740935.pdf
    • http://hajnysport.cz/FCK_userfiles/file/fimiwumufokalejiropogo.pdf
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/9dokmlu82hu5t9sv11td4dlnp2/51341270075.pdf
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f87f9652860---jonarufivajowalemuti.pdf
    • http://wildpflanzen-planung.de/file/670864867.pdf
    • https://rtvpuls.com/ckfinder/userfiles/files/zenem.pdf
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/e2it59ut351m6pr2q7elm6aefj/79331916807.pdf
    • http://msiutilities.biz/documents/goputonetarejij.pdf
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1608d953a2922a---buzogawijojokuvaxaxetak.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_off0000cd88.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCD88 16792 bytes
font_01_sfnt_off0000e59f.bin
64574436bb89633ed2e4d4a73aeb062b6e3b8a3295a16ed101e85374f2c5fc9f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE59F 10476 bytes
font_02_sfnt_off0000fd52.bin
90b7ab5709777e3394fe80809084f4796cf4ea0a9366134a5b71f44fe283af26
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD52 17728 bytes