Malicious PDF — malware analysis report

Static analysis result for SHA-256 8133752cb5dc5130…

MALICIOUS

PDF

119.5 KB Created: 2021-07-18 04:42:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: aeb1d4a83684ac9567cf947cdbf8a621 SHA-1: d3c4cb398be2ffa2ea42382c2f27d843d670a25a SHA-256: 8133752cb5dc5130bd7650ce8c16120a7f5d5be130f4c91aec1927bc9f21094d
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://itchanoi.vn/uploads/news_file/54866115446.pdf In PDF document text
    • https://susta.vn/userfiles/file/sajoxurumagonolepivo.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/73558662472.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad3d8ca86ed---46413556391.pdfIn PDF document text
    • https://alshamiltrading.com/alshamilfiles/file/45384399634.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609c1073be7da---33020289917.pdfIn PDF document text
    • https://www.sensiblemachines.com/ckfinder/core/connector/php/files/91795492005.pdfIn PDF document text
    • https://cspdental.com/wp-content/plugins/super-forms/uploads/php/files/f5d86aee309d28e1a4daaed1ce4823c2/dizakevipivarajufamiv.pdfIn PDF document text
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbef0cbfa2---wunadenizanowomekirupido.pdfIn PDF document text
    • http://hani-bee.com/userfiles/files/girufozavifona.pdfIn PDF document text
    • http://mtprospectbaptist.org/clients/7/74/74f10a8404da00fab064704771972c19/File/zubejadapomarazaniw.pdfIn PDF document text
    • https://pointswestliving.com/ckfinder/userfiles/files/52957305195.pdfIn PDF document text
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/banere.pdfIn PDF document text
    • http://teenmag.cz/userfiles/file/36340010067.pdfIn PDF document text
    • http://gorisum.net/fckeditor/upload_file/file/11454172491.pdfIn PDF document text
    • https://okud-istra.hr/userfiles/file/97108565620.pdfIn PDF document text
    • http://optimus.org.au/wp-content/plugins/formcraft/file-upload/server/content/files/160baec65afbc8---65135923088.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=oasis+live+1994PDF 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_off000170b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x170B1 18548 bytes
SHA-256: 9db9c3a07fd8056a40db49428f093853d90ea4120fcd260770cb43744042ab79
font_01_sfnt_off0001a194.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A194 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001b9ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B9AB 10068 bytes
SHA-256: b9ffec525a7d25c5cbb722b7e916a928d3a6fb3745b47242da5caf029bd9e2fe