Malicious PDF — malware analysis report

Static analysis result for SHA-256 748a8d9ecb0c73cf…

MALICIOUS

PDF

70.4 KB Created: 2021-09-30 10:11:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 73c5da6fb28d8bd084f4bac08697d28c SHA-1: 5e22378a0e6dd750aef5981744a18449b5d4145a SHA-256: 748a8d9ecb0c73cf64aa3868384e05cf9c1ce5f152589aa912d92e8ac5b3c3e9
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The presence of numerous external URIs, many pointing to potentially disposable domains, suggests a link farm or phishing lure. Although no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's designed to redirect users to malicious sites, likely for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://zagorjeadventureteam.hr/files/rekanekogufubexu.pdf In PDF document text
    • https://manajrgvaaradhi.com/cms-uploads/files/solukilila.pdfIn PDF document text
    • http://climacom.eu/userfiles/files/16878844909.pdfIn PDF document text
    • http://lambanghieuquangcaogiare.net/vietkiendo/upload/file/kutirojozetefu.pdfIn PDF document text
    • http://brickchamber.com/ckfinder/userfiles/files/warigar.pdfIn PDF document text
    • https://weborder.cloud/userfiles/file///41520199222.pdfIn PDF document text
    • https://muahohangnhat.com/app/webroot/uploads/files/tutuwibilejugofisilogo.pdfIn PDF document text
    • https://pass-eco-energies.com/ckfinder/userfiles/files/sanirukiba.pdfIn PDF document text
    • http://nuovojob.com/userfiles/files/89825323479.pdfIn PDF document text
    • https://cottingham-group.com/cufiles/files/17755490246.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161318d884c9df---27524996131.pdfIn PDF document text
    • http://loaamtran.vn/files/usersfiles/files/bavuvivofigopesofakigum.pdfIn PDF document text
    • http://midospa.com/upload/files/95980328350.pdfIn PDF document text
    • https://nakatarikaszel.pl/app/webroot/userfiles/file/nigekatefenafawobe.pdfIn PDF document text
    • http://zeamailer.zeapost.com/FCKeditor/editor/filemanager/connectors/userfiles/file/61898708534.pdfIn PDF document text
    • https://wonkingchina.com/d/files/85361167690.pdfIn PDF document text
    • http://maymaygiaydachidang.com/upload/files/befusepe.pdfIn PDF document text
    • https://venusnvs.com/userfiles/file/wibumakiwabapib.pdfIn PDF document text
    • http://cioccolatogallucci.it/userfiles/file/virizo.pdfIn PDF document text
    • https://stmarys-perthamboy.com/upload/File/33405960575.pdfIn PDF document text
    • http://halongbaycruises.org/upload/files/1237272982.pdfIn PDF document text
    • https://llbyggodesign.se/UserFiles/files/nodoketiximakazokapudi.pdfIn PDF document text
    • https://www.andeanskyline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613aa53a6f687---fizejexujezofugoso.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=relation+between+wavelength+frequency+and+time+periodPDF 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_off0000affb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFFB 16484 bytes
SHA-256: 5f281d7437fe50066a7e6d6e092b4f0ef1624968627b69efc4d2a5d5e37a8c5a
font_01_sfnt_off0000d956.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD956 11596 bytes
SHA-256: 3aa526a680ccb1db24ed7f9118a61f5b0421103e160474e07b3fbfa8d7152897
font_02_sfnt_off0000f403.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF403 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1