Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a16ca7ac432612e…

MALICIOUS

PDF

86.6 KB Created: 2021-09-21 04:37:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 9bfec779904e776b8aca001e3d45dcf4 SHA-1: 732c3fb0cd55547d8e0e5ded760155da3cff0169 SHA-256: 8a16ca7ac432612e146ad718a1be8dadc4926ca045a73aed7d7555577a0e024f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The presence of multiple external URIs and link farm heuristics supports this conclusion.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://cliniquemyo.com/userfiles/file/94347242259.pdf In PDF document text
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/1e92dfe0347f39450ceaaceeaf91a6df/17434140233.pdfIn PDF document text
    • http://www.facyt.com.ar/ckfinder/userfiles/files/pimanixitamisexoza.pdfIn PDF document text
    • http://xy-interior.com/uploads/files/202109062138223853.pdfIn PDF document text
    • http://thedewakohchang.com/image/upload/File/erumoniju.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613ad4cf5f6d9---binuvejatabopadiguvon.pdfIn PDF document text
    • https://gplacestracker.com/userfiles/file/lapodefixuduvetinodojikuf.pdfIn PDF document text
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16144448f3a650---kokakeriruxar.pdfIn PDF document text
    • http://musik-fachberatung-neumarkt.de/images/uploadedimages/file/woxovifotoxalumufuvivul.pdfIn PDF document text
    • http://vagtteam.com/userfiles/Files/19020723128.pdfIn PDF document text
    • https://toolsatool.com/userfiles/files/zagagesererizisumasupo.pdfIn PDF document text
    • http://ttworld.hu/uploads/content_files/files/kosidovijegewoj.pdfIn PDF document text
    • http://szwygs.com/upload/98282329087.pdfIn PDF document text
    • http://glamour-nsk.ru/ckfinder/userfiles/files/goduzugitasifewubeve.pdfIn PDF document text
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613048a0823a4---mibexen.pdfIn PDF document text
    • https://vilnius.cvzona.lt/resources/img/files/44371741715.pdfIn PDF document text
    • http://vasvaripalmuzeum.hu/upload/file/gutipuvotomar.pdfIn PDF document text
    • http://proximeo.com/ckfinder/userfiles/files/67051316009.pdfIn PDF document text
    • https://psg66.ru/admin/ckfinder/userfiles/files/belegakixew.pdfIn PDF document text
    • https://b7b.reviewz.eu/app/webroot/files/userfiles/files/78534509329.pdfIn PDF document text
    • https://toyotaautobody.com/ckfinder/userfiles/files/62225458803.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=spooks+series+6+episode+8PDF 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_off0000eecd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEECD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000106df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106DF 17728 bytes
SHA-256: c986d63f48bcf096d7200116e0cb167528e45219a47af38096fe61ea5c2e28b6
font_02_sfnt_off000134e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134E6 10516 bytes
SHA-256: fb17f92fbec50ea47e8a1d6ec7c70dda16dab619b8311a9f59b9263b7dded3b0