Malicious PDF — malware analysis report

Static analysis result for SHA-256 4653834a35ef52c9…

MALICIOUS

PDF

85.1 KB Created: 2021-09-10 20:50:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: d36d032ada796536fde488a8c19e21b2 SHA-1: 457dd20a610deeaea8b65a3b2a5036146e08449d SHA-256: 4653834a35ef52c9a01692041e30cd70ee23d8009f30ca3e490ccdf8ba957f0b
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous external URIs and links pointing to disposable hosting and compromised CMS uploads, suggesting an attempt to redirect users to malicious content. The presence of these links strongly implies a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://cructi.ru/uplcv?utm_term=how+clear+internal+storage PDF link annotation
    • http://runhouchem.com/upload/files/xupelawofibig.pdfIn PDF document text
    • https://dcoderesearch.com/uploads/mites.pdfIn PDF document text
    • http://daindnc.com/fckeditor/userfiles/file/fafizofiwaduduzewu.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/hmgnbmfqre0c1ortbcnvf88ujk/64670207689.pdfIn PDF document text
    • http://paillasse.hu/userfiles/file/34037932525.pdfIn PDF document text
    • http://metisentry.net/ckfinder/userfiles/files/68535419389.pdfIn PDF document text
    • http://cck-brno.cz/ckfinder/userfiles/files/modifutiroxeko.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/01182bae9e831417fa05534a877c97ae/50045886156.pdfIn PDF document text
    • https://palet-school.com/files/files/dopanoladut.pdfIn PDF document text
    • http://canadianrockies.info/files/file/21626868412.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1612fdd33dbeb9---57437057346.pdfIn PDF document text
    • http://vervesimuhub.com/userfiles/file/kobejifojeb.pdfIn PDF document text
    • http://1yunnan.com/ckfinder/userfiles/files/ruberosajobaladixi.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/161361d5035193---2725243952.pdfIn PDF document text
    • http://candemdientu.com/Images_upload/files/fozetemafit.pdfIn PDF document text
    • http://triatlonbizuterie.cz/sites/default/files/file/30720037980.pdfIn PDF document text
    • https://pre-www.bridge-college.com/uploaded/ckeditor/files/denavapaludegugipuweladu.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/19777248124.pdfIn PDF document text
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613033f4be091---dexejibifuxokejuleve.pdfIn PDF document text
    • http://hemeringen.de/ckeditor_ablage/userfiles/files/11598188020.pdfIn PDF document text
    • https://psychologgia.pl/Upload/file/26261808199.pdfIn PDF document text
    • http://jewelry-shopping-city.com/uploads/files/202109101048216218.pdfIn PDF document text
    • https://arte-salon.ru/upload_picture/suxosagirokanisutut.pdfIn PDF document text
    • http://geoscan.it/userfiles/files/segifunurabib.pdfIn PDF document text
    • https://letstravelforacause.com/miet/assets/files/69039517777.pdfIn PDF document text
    • 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_off0000e61f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE61F 18928 bytes
SHA-256: 57bc04f9a86e843ac8ae9564ba71ecb2c245cb57196eec8b48d4ff89a539bef8
font_01_sfnt_off0001168f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1168F 10480 bytes
SHA-256: 069bdae3853d2ab159bb4c9174a338324955c1a543934fa84ed5e47bb8aa3f8b
font_02_sfnt_off00012e85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E85 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1