Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac20e51548f29550…

MALICIOUS

PDF

82.4 KB Created: 2021-08-26 13:45:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: f77bc52453070acef139d9bd4f24e64e SHA-1: 3dc0d887a911d85fa45a5c7577611eff4378ecdf SHA-256: ac20e51548f29550e474ccf0783af1bcb99138ae63bfe109a9f078d737914a4d
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The file's structure and URL distribution align with a link farm designed to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://oumkua.com/userfiles/file/30449578332.pdf In PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/161094f2536465---91074900473.pdfIn PDF document text
    • http://cokhihoaiduc.com/uploads/files/lefefovaxudazi.pdfIn PDF document text
    • http://trunghungplastic.com/luutru/files/vudinupegozibetasekaz.pdfIn PDF document text
    • http://kapsalonindex.nl/images/uploads/78033685043.pdfIn PDF document text
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080b0f9d2f91---57044307140.pdfIn PDF document text
    • https://ddtoyz.com/ckfinder/userfiles/files/68802601441.pdfIn PDF document text
    • http://flemingfamilies.org/clients/8/8a/8af36a28baf44bfc7b8a7004fb4eaede/File/gelud.pdfIn PDF document text
    • http://anvlaw.com/userfiles/file/67374756971.pdfIn PDF document text
    • http://cichanski.com/Upload/file/zimazesube.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/1610901abe0421---87631368841.pdfIn PDF document text
    • https://aduanaldelvalle.com/userfiles/file/juzotofup.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160774c615e983---fasuxujeregenorurakorut.pdfIn PDF document text
    • https://stef-nancy.fr/upload/document/vejobivikitigokojiwararox.pdfIn PDF document text
    • http://tavaszitura.eu/userfiles/files/wamasofakipozowedorapenet.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607d3196cc7f3---tumowumomufixamipuxomep.pdfIn PDF document text
    • http://teaandtiarasottawa.org/clients/e/e8/e8f54e69a7463df9fd0adff13cd8e90f/File/duwofen.pdfIn PDF document text
    • http://shbaicun.com/userfiles/file/2021081618180573499.pdfIn PDF document text
    • http://dui-antidote.net/images/userfiles/file/79649773273.pdfIn PDF document text
    • http://hosungtour.com/FileData/ckfinder/files/20210712_14D9542970B8DC39.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=best+mottos+to+live+byPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF1D 10276 bytes
SHA-256: 40932ad68213f2951b4e67cc3d45790b454a4e08c8bf26ed04652b3ad45cfe8d
font_01_sfnt_off0000f658.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF658 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E6A 17768 bytes
SHA-256: e024f1f07e0717ace78eca6bdb9dd30dff77130d569f46cc937b3a9a223229c0