Malicious PDF — malware analysis report

Static analysis result for SHA-256 1553ff1efbe81c68…

MALICIOUS

PDF

92.0 KB Created: 2021-09-15 20:58:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c30d3514de9523f793f143f40a61aa43 SHA-1: 27f8e96559027443074db6db2aab096a1a24d4bc SHA-256: 1553ff1efbe81c680be6bfa37fc7961be9a55e94d2b78fe841283f61b62673a7
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to other PDFs hosted on disposable domains, presented as a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a tactic to distribute malicious content through a large number of low-reputation domains. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • 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 http://timavoshipsupply.it/userfiles/file/91772751610.pdf In PDF document text
    • http://ahcxdq.com/uploads/file/010949366952.pdfIn PDF document text
    • http://boek.se/bilder_umeny/File/82075988061.pdfIn PDF document text
    • https://ryokanclub.com/FileData/ckfinder/files/20210915_740F9A6AE9DF871D.pdfIn PDF document text
    • https://mikludava.lt/images/files/71586060685.pdfIn PDF document text
    • http://knowleangling.co.uk/ckfinder/userfiles/files/vilixigerugugefufizoz.pdfIn PDF document text
    • http://ebara.com.hk/ckfinder/Zenith/userfiles/files/wifomizowunapatela.pdfIn PDF document text
    • https://sharmtocairo.com/userfiles/files/vamalifu.pdfIn PDF document text
    • http://7m-shop.com/userfiles/file/ponabun.pdfIn PDF document text
    • http://masterref.ru/editorfiles/file/54442370805.pdfIn PDF document text
    • http://fgosvo.ru/files/files/2593532376.pdfIn PDF document text
    • http://tdbakademi.org/userfiles/files/32587812067.pdfIn PDF document text
    • https://vzglavniki.net/data/file/tifiloxevatemanitela.pdfIn PDF document text
    • http://terremeraude.com/userfiles/file/25027381345.pdfIn PDF document text
    • http://charmingcurls.se/upload/file/2321338014.pdfIn PDF document text
    • http://altronic.pl/!mag2011/userfiles/file/lemanukanexezokafifabeb.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137ac7c2279a---57025832731.pdfIn PDF document text
    • http://profitoolinfo.ru/ckfinder/userfiles/files/23617396432.pdfIn PDF document text
    • http://tvkinter.com/file_media/file_image/file/pokobesifuwalekugixetok.pdfIn PDF document text
    • http://dui-antidote.com/images/userfiles/file/nujosovawemufokokepujow.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614161fbbe985---22587641720.pdfIn PDF document text
    • https://sambelteri.com/contents/files/24668259197.pdfIn PDF document text
    • http://enslev-anlaegsservice.dk/userfiles/file/19130639486.pdfIn PDF document text
    • https://www.verimevzabavu.cz/ckfinder/userfiles/files/gajafofo.pdfIn PDF document text
    • http://ordinate-ltd.com/file_media/file_image/file/8296296542.pdfIn PDF document text
    • http://altronic.pl/!mag2In macro / runtime command snippet
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=autodesk+revit+2016+serial+number+and+product+key+crackPDF 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_off00010049.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10049 17720 bytes
SHA-256: 3baea691ebe651c32a922656dc5d5498713d3b5a53ae0ee439fda408d7a12106
font_01_sfnt_off00012e2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E2C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014643.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14643 11628 bytes
SHA-256: 45fad51f5e8dc906f00b68029ee1c8dfc90c4ce35c0ea32f6dc3a76956dcec3d