Malicious PDF — malware analysis report

Static analysis result for SHA-256 de53f81a81e7ba37…

MALICIOUS

PDF

73.8 KB Created: 2021-09-28 08:50:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 6bed27141c39d352ee5531fa033f6c98 SHA-1: 77624a954550a245416516223333d3ab769986f2 SHA-256: de53f81a81e7ba37106d28c0e089ae2a6e8b6dae8b8862417345ce3c480224d1
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ML classifiers and ClamAV as malicious, indicating a phishing or malware distribution attempt. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and the numerous extracted URLs suggest the document's primary purpose is to redirect users to potentially harmful websites. No scripts were extracted, but the presence of embedded URLs and the link farm characteristic strongly suggest a phishing or malware delivery vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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://euronuts2009.ge/files/files/poxonukagunizidasowadelap.pdf In PDF document text
    • http://abnicum.ru/files/file/30380875873.pdfIn PDF document text
    • http://tidomusica.com/uploads/files/202109121016147290.pdfIn PDF document text
    • https://nguyenvanhuongloc.vn/app/webroot/files/images/pages/files/6458342808.pdfIn PDF document text
    • https://rsvforum.com/userfiles/file/36581744888.pdfIn PDF document text
    • http://charmingcurls.se/upload/file/tidejesododebom.pdfIn PDF document text
    • http://373113.linker.tw/files/xufixibigutefobavuxuvev.pdfIn PDF document text
    • http://gonganmi.com/userfiles/file/45836189022.pdfIn macro / runtime command snippet
    • https://www.thic.net/plugin/ce1/ckfinder/userfiles/files/poregodikodeniniboj.pdfIn PDF document text
    • http://inewbus.com/wp-content/plugins/super-forms/uploads/php/files/0ao1e8tvk5f3gp3eas6umhu4m5/xuvaroxan.pdfIn PDF document text
    • http://cambridgekapurthala.com/damana/userfiles/file/wupinabebonopurozik.pdfIn PDF document text
    • http://thy-environment.com/userfiles/files/15988860235.pdfIn PDF document text
    • http://herbwaterthailand.com/userfiles/files/gofosefinova.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/16131f9222ed29---tisujafuku.pdfIn PDF document text
    • https://inunekocp.jp/mailmagazine/upload/files/5638457974.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/f1c91f66045eddf223f4f0d1a1833bfd/62206069903.pdfIn PDF document text
    • http://www.gpkoaee.ru/ckfinder/userfiles/files/1470914407.pdfIn PDF document text
    • https://chambres-lannion.fr/userfiles/file/17672429918.pdfIn PDF document text
    • https://nissanzorba.ro/ckeditor/ckfinder/userfiles/files/nopuvejejopuwepagi.pdfIn PDF document text
    • http://strahyi.ru/images/file/27778652469.pdfIn PDF document text
    • https://castilloexterior.es/ckfinder/userfiles/files/piwurosu.pdfIn PDF document text
    • https://glozorcom.merlak.ru/userfiles/file/71191941914.pdfIn PDF document text
    • https://granitabrasive.ro/editor_up/26284392019.pdfIn PDF document text
    • https://lwim-ouargla.dz/ar/files/45704339432.pdfIn PDF document text
    • http://373113.linkeIn macro / runtime command snippet
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=how+do+you+put+a+widget+on+your+home+screenPDF 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_off0000b515.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB515 19164 bytes
SHA-256: a77ad7fba82b341b562889fb223ad6bdb8af75d56efd03452180b04f28dcfc71
font_01_sfnt_off0000e5d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5D6 11208 bytes
SHA-256: 273c4e6783f6f97b88100a19830f019f53785771f9d35149a6713b1e2cfda73a
font_02_sfnt_off0000ffbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFBE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1