Malicious PDF — malware analysis report

Static analysis result for SHA-256 e2091279b6e0b87a…

MALICIOUS

PDF

82.3 KB Created: 2021-09-15 10:05:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 71b1e27a8d88e6e6715e057a937860bf SHA-1: 1a9ebae741bbbef4491025b0b916930f6cfd269c SHA-256: e2091279b6e0b87af74efdb927b22a87857a20291159974c20e33a4ddd9f0013
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV and an ML classifier as malicious. It contains numerous embedded URLs pointing to various domains, and a heuristic identified it as a link farm on disposable hosting. The PDF_URI heuristic specifically extracted a URL that appears to be a redirector. While no scripts were explicitly extracted, the presence of multiple external links and the link farm heuristic suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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 https://synerhu.ru/uplcv?utm_term=positive+words+from+r PDF link annotation
    • http://hsound.ro/images/custom/file/76241179585.pdfIn PDF document text
    • http://yuha.be/_files/file/57844390075.pdfIn PDF document text
    • https://serrechevalier-skifun.com/imagesfile/26098418312.pdfIn PDF document text
    • http://wellogo.in/userfiles/file///bikokuneduxi.pdfIn PDF document text
    • https://molecult.metallo-tests.ch/sites/web/upload/files/57426548546.pdfIn PDF document text
    • https://quatcongnghieput.com/uploads/files/57924065559.pdfIn PDF document text
    • http://putzlappenborner.at/editor_up/delurulexex.pdfIn PDF document text
    • http://gartenmessebau.de/uploads/files/ronokobub.pdfIn PDF document text
    • https://jackinthegymtpe.com/uploads/files/202109051925537291.pdfIn PDF document text
    • https://leganordavigliana.it/uploads/file/9046469904.pdfIn PDF document text
    • http://stepasidemedical.ie/images/uploads/file/lepujalekivufura.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/p7pn6qc9i5koo2adb24gqjiofu/xivekuroferilib.pdfIn PDF document text
    • http://sp3siemianowice.pl/userFiles/files/farotufulekip.pdfIn PDF document text
    • http://ingmontagna.com/userfiles/files/lalorivawukedodiwujef.pdfIn PDF document text
    • http://asesorgubernamental.com/images/file/49513555716.pdfIn PDF document text
    • https://valerart.com/ckfinder/userfiles/files/vozuwuwo.pdfIn PDF document text
    • https://christianklein.eu/Quansis/ckfinder/userfiles/files/56822394958.pdfIn PDF document text
    • http://ctcinsulator.com/uploads/file/bezemadugolumepip.pdfIn PDF document text
    • http://pumarecovery.com/userfiles/files/vibizusutatuluzexor.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614140443459f---36371826593.pdfIn PDF document text
    • https://conexkarvan.com/cache/fck_files/file/jafepuv.pdfIn PDF document text
    • http://rnralpha.cz/res/file/tewur.pdfIn PDF document text
    • http://cx-gl.hu/images/files/71117015060.pdfIn PDF document text
    • https://thehouseconcert.com/ckfinder/userfiles/files/44292876262.pdfIn PDF document text
    • http://retailcop.ca/files/33167112820.pdfIn PDF document text
    • http://hysansam.com/fckeditor/userfiles/image/fojapoxujupewed.pdfIn PDF document text
    • 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_off0000dd8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD8A 18004 bytes
SHA-256: d37008d3318f43afa3fbdd9c81f9cc1faffccbec55815d2ce749c7249a789115
font_01_sfnt_off00010b74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B74 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001238b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1238B 10356 bytes
SHA-256: 94e22b8ac9dd9d24585e7fa2a8c846a3825cb0cade5f8946141b0388f1e3f2ce