Malicious PDF — malware analysis report

Static analysis result for SHA-256 816b9cae39b7524f…

MALICIOUS

PDF

121.0 KB Created: 2021-09-05 07:30:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 6d5131a0a95ae3e06cc2a34871bca27a SHA-1: f90f545d05005ee9f3e4b5e663c16c5ab1d3e9cf SHA-256: 816b9cae39b7524f79bf2bc07b2ca29c9bf5f355bd235d944e4c4cf18a5b2a42
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm pointing to multiple domains, several of which appear to be compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically phishing. The presence of numerous external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic suggest the document's primary purpose is to redirect users to potentially malicious sites.

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://baongochoa.com/upload/file/29526488228.pdf In PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/16086eeb771815---93421283132.pdfIn PDF document text
    • http://gaudi.tw/upload/file/xekevemalewafajis.pdfIn PDF document text
    • http://reutlinger.pl/userfiles/file/nariduvalosexazisafi.pdfIn PDF document text
    • https://ideylia.fr/uploads/file/vazunot.pdfIn PDF document text
    • https://canadianrelocation.net/wp-content/plugins/formcraft/file-upload/server/content/files/16087624232694---kababibozulizeluf.pdfIn PDF document text
    • https://limsurempat.com/contents/files/sumunukajezoluvonesapifi.pdfIn PDF document text
    • http://kajsanordstrom.com/userfiles/files/37155477655.pdfIn PDF document text
    • https://euroroma-bg.org/files/file/mebazaxidebib.pdfIn PDF document text
    • http://msinziniering.com/userfiles/file/21850907038.pdfIn PDF document text
    • https://jjmassociates.com/wp-content/plugins/super-forms/uploads/php/files/6ee54fd46ecf8707d8a3d5734da0bbc1/1008619676.pdfIn PDF document text
    • https://xlspandoek.nl/userfiles/file/duwosuwizixiweponor.pdfIn PDF document text
    • http://oroszvilag.hu/userfiles/file/36188057655.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/a709b0eca4edf83de0dec090c6849bca/duditorizokoziwow.pdfIn PDF document text
    • http://metrokentakifinan.com/resimler/files/90891760863.pdfIn PDF document text
    • https://franchiseharbor.com/files/files/79383137498.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac9d3e115d7---banamajamodelesopi.pdfIn PDF document text
    • http://www.alcera.ca/userfiles/file/xefom.pdfIn PDF document text
    • http://leaguengn.com/userfiles/file///46328300776.pdfIn PDF document text
    • https://dichvumoinoi.com/ckfinder/userfiles/files/91074474230.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/93455802577.pdfIn PDF document text
    • http://chistogood.ru/admin/ckfinder/userfiles/files/71350104452.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/matezejepurobelu.pdfIn PDF document text
    • http://rogo-rotterdam.nl/files/30159018797.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=libro+quimica+inorganica+santillana+pdfPDF 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_off00016c31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16C31 11176 bytes
SHA-256: 2b7b30f833b7b29c2c56d4add568ed6f189459836dfa5ecbd4b5e6d6edf6fda7
font_01_sfnt_off0001858b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1858B 21504 bytes
SHA-256: ba5995384111c8de666dc13d9fa5e4386dd681fac64cf64370a8689ade7121f7
font_02_sfnt_off0001bbc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1BBC9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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