Malicious PDF — malware analysis report

Static analysis result for SHA-256 99a5672f3c72c100…

MALICIOUS

PDF

73.2 KB Created: 2021-08-14 09:58:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e230d5a0ce8fafca17b9dffd92d7122e SHA-1: 825b3625ede5452870f32b95fd987df7a22962b1 SHA-256: 99a5672f3c72c100ca9b52b5fedc7b8e9c251370872387305355660ccadc1cd3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous links, many pointing to compromised WordPress sites, suggesting it functions as a link farm designed to redirect users to potentially malicious content. The presence of embedded URLs and the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicate a deliberate attempt to obscure the final destination and potentially distribute malware or conduct phishing. No scripts were extracted, but the structure strongly suggests a lure for initial access.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://polskieplytki.com/wp-content/plugins/super-forms/uploads/php/files/f0dda8a48b75f4223114389bad834ec8/somakudaf.pdf
    • https://www.brightfieldbusinesshub.co.uk/wp-content/plugins/super-forms/uploads/php/files/nr0d9qhoj0ppegq12b9ch34bbt/zamim.pdf
    • https://www.projectorrentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610071515afbc---84950606057.pdf
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/23bd6109b9b2600cc38fbbeab7852365/51783534052.pdf
    • https://deniz-sogutma.org/img/userfiles/file/wimidafeza.pdf
    • http://bioscipublisher.com/files/upfiles/file/kivevuwogijevijemegew.pdf
    • https://loctra.net/userfiles/file/76347681545.pdf
    • http://xn--or3bi2da319p.com/upload/fckeditor/file/boxinoxorofirixakexek.pdf
    • http://goldenteriyaki.com/uploads/files/22967872109.pdf
    • https://stallion-international.com/userfiles/file/tawurizenuf.pdf
    • http://spearsyounglegacy.com/clients/b/b2/b2c23f164518415ec8f3c1c8d0af542d/File/64876516090.pdf
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/8d0730d31b26ef088709d32e355ca85a/dikefefizifajufuniri.pdf
    • http://exclusivelimoservice.com/ckfinder/userfiles/files/20722085822.pdf
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/89qsjvghlh3flfuq919sudasit/nozenut.pdf
    • https://terravistahometeam.com/wp-content/plugins/super-forms/uploads/php/files/cfd60dde8b6e5ac29158a9438a5b04f6/tubebituxapew.pdf
    • http://shtaket46.ru/page_edit/_samples/userfiles/files/69840943070.pdf
    • http://szzxwx.com/Upload/Upload/file/2021751215155007.pdf
    • http://jakebenmd.com/clients/0/0e/0eef9d569b11303d075d19626cc6f958/File/denodiroki.pdf
    • http://sorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/nakoduvetujul.pdf
    • https://futuresbuilder.net/dayafter/uploadimages/newsimages/file/55683637088.pdf
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/pq9eocld0n1og517tque58f89q/gipidarere.pdf
    • https://smilepath.com.au/wp-content/plugins/super-forms/uploads/php/files/f166551ef754ce6f7682a9a51f3b0ccc/33851171214.pdf
    • http://linkingpeople.info/userfiles/file/35115004262.pdf
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160a24e5480e2a---nezetomojobutu.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=square+numbers+worksheet+year+6
    • 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_off0000bcd0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBCD0 16792 bytes
font_01_sfnt_off0000d4e2.bin
2f5d811b06bd5a0cf5dcf1a6a1f06ffd1e555b86a063f25e8927e8e20b1b8a53
pdf-font-stream PDF embedded font (sfnt) at offset 0xD4E2 15684 bytes
font_02_sfnt_off0000fd3e.bin
b7036b4707c2a572f25549e795c8a22cc0c247f5bd8c0bc3eed009f55768f8fd
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD3E 11156 bytes