Malicious PDF — malware analysis report

Static analysis result for SHA-256 a167d60aec18d3b5…

MALICIOUS

PDF

93.7 KB Created: 2021-10-07 15:06:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-07
MD5: dee4ade4141713b725053fb932491a4f SHA-1: 56d5b90e3dc2d8a84bf23a56f21fa6c437ad27d5 SHA-256: a167d60aec18d3b55b13d6462e660dbec72fe3a3c38dccdc3aee89a86780ba8c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected by ClamAV as a phishing trojan and flagged by an ML classifier. It contains numerous embedded URLs that point to external PDF files, suggesting a phishing or link-farming attack. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further indicates a pattern of using disposable hosting for these links, likely to evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://coral-travel66.ru/admin/ckfinder/userfiles/files/zusuruto.pdf In PDF document text
    • http://starinviter.com/ckimagefiles/24065399112.pdfIn PDF document text
    • http://artwatch.ru/userfiles/file/79285809656.pdfIn PDF document text
    • http://www.sm.ac.th/ckfinder/userfiles/files/73514993950.pdfIn PDF document text
    • http://studioarchterreni.it/userfiles/files/82344049399.pdfIn PDF document text
    • http://yuemeism.com/uploadfiles/files/dijizepunonatupobotalima.pdfIn PDF document text
    • http://xboxheerlen.nl/userfiles/file/raluzubeganudenivegoma.pdfIn PDF document text
    • http://parejalecaros.com/adjunto/upload/fck/files/11936526701.pdfIn PDF document text
    • http://gpmpoolandspa.com/ckfinder/userfiles/files/7259206019.pdfIn PDF document text
    • http://solarwindependence.com/ckfinder/userfiles/files/vixupowotenusatorifila.pdfIn PDF document text
    • http://pamatudarbai.lt/ckfinder/userfiles/files/25233778099.pdfIn PDF document text
    • http://danbikoreansj.com/uploads/files/95654492501.pdfIn PDF document text
    • http://lynxauto.ru/userfiles/file/52321605062.pdfIn PDF document text
    • https://bgg.pirkitpadangas.lt/ckfinder/userfiles/files/warazodelavutojivifovoxug.pdfIn PDF document text
    • https://korvioinfotech.com/ckfinder/userfiles/files/xowenuvinanesora.pdfIn PDF document text
    • http://www.southforconstruction.com/frontend/web/ckfinder/userfiles/files/pukisi.pdfIn PDF document text
    • http://kerrya.com/ckfinder/userfiles/files/dikanetotenajibivuk.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/75d7bba6643a7e14a513534eab311bf1/43412555390.pdfIn PDF document text
    • http://radecznica.pl/userfiles/file/ginati.pdfIn PDF document text
    • http://leylatoprak.com/userfiles/file/61867457659.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/mixixogizemuvatubilixito.pdfIn PDF document text
    • http://whuntex.ru/userfiles/file/67231797614.pdfIn PDF document text
    • https://thietbivesinhsonhoa.com/webroot/img/files/81876145856.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=fun+easy+quizzes+and+answersPDF 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_off000102b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102B3 10460 bytes
SHA-256: dc1481473cd78ccb2539e502b3e6f362bd7338f3526735b8651a3a70565df6fb
font_01_sfnt_off00011a6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A6D 21460 bytes
SHA-256: 8a4b6d863d30ca983c00ca426c0357db034800f90a1458d0330b81ecb53adaa3
font_02_sfnt_off0001513a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1513A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1