Malicious PDF — malware analysis report

Static analysis result for SHA-256 9f668ac66f48e89b…

MALICIOUS

PDF

70.0 KB Created: 2021-09-25 01:04:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 33e37acde3aeb7e1915c89f5541c53ca SHA-1: b515fc8f25b0ef134e1f741a78c6e35ed65dd457 SHA-256: 9f668ac66f48e89b882e72dea39fb08d0a8986c048699e758ed1a47c0b4dc347
134 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. The PDF also contains numerous external URIs, many of which point to disposable domains and appear to be part of a link farm. This suggests the primary purpose is to redirect users to potentially malicious websites, likely for phishing or to download further malware. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://0vote.com/ckfinder/files/tozixuzokesodipe.pdf In PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614ad3c9ccf77---burifumol.pdfIn PDF document text
    • https://dalton-english.com/userfiles/file/77962744818.pdfIn PDF document text
    • http://sm.ac.th/ckfinder/userfiles/files/84077080052.pdfIn PDF document text
    • https://condicionamentofisico.com/arquivos/file/36029678157.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/88e3711ee95f48792d1ee8543fe38c72/73767845299.pdfIn PDF document text
    • https://grootformaatspandoeken.nl/userfiles/file/1183593271.pdfIn PDF document text
    • http://palestraarkadia.it/userfiles/files/76416107789.pdfIn PDF document text
    • https://ahl2005.com/ckfinder/userfiles/files/wivokozanegofigakeruxowo.pdfIn PDF document text
    • http://factblogs.com/uploaded_files/userfiles/files/jupapekixo.pdfIn PDF document text
    • https://arabadvertise.com/userfiles/files/zowevinomupagegatet.pdfIn PDF document text
    • http://orthopediedelft.eu/files/mubenu.pdfIn PDF document text
    • https://ptogel1.com/contents/files/10521930253.pdfIn PDF document text
    • http://radioevangilereal.com/assets/ckfinder/core/connector/php/uploads/files/viseneninafupum.pdfIn PDF document text
    • https://perfecthospitals.org/FCKeditor/file/85392981091.pdfIn PDF document text
    • http://progettogeometra.it/userfiles/files/zosolupitakijudobivisiva.pdfIn PDF document text
    • http://hoangminhsaigon.vn/@dmin/js/ckfinder/userfiles/files/dadif.pdfIn PDF document text
    • https://it-remarketing.pl/app/webroot/media/files/tuzifumosaxipebus.pdfIn PDF document text
    • https://vmgeducationtrust.org/home/vmgedu/public_html/public/userfiles/file/xufivuzozodiregesaw.pdfIn PDF document text
    • https://kligi.viart.lt/ckfinder/userfiles/files/58158535377.pdfIn PDF document text
    • https://xn--nmqu14inmf.com/upload/files/99729217679.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=meaningful+words+that+start+with+ePDF 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_off0000b013.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB013 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c82a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC82A 10812 bytes
SHA-256: 806e94b4521ecaf2e5b0762b283d79dcfa8d6095af91fe70ae4a6d7bf1aedc74
font_02_sfnt_off0000e0e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0E5 16252 bytes
SHA-256: d6aa32029fed5cf01bf83ac38848d3ff05a264dc313b3d3760698d5ddfe237ef