Malicious PDF — malware analysis report

Static analysis result for SHA-256 d44bdfa4aba09edd…

MALICIOUS

PDF

69.5 KB Created: 2021-04-26 23:13:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 8081a8a2485ec0964f0ffda4cb51176d SHA-1: c9b829a53a2a1ef9a6ba9c96fe7479caf809e312 SHA-256: d44bdfa4aba09eddd154df5178e830e502a50edd111770eacb279cad8f497d3c
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which are part of link farms and point to potentially malicious domains. The document body, though heavily obfuscated, contains keywords related to router login, suggesting a phishing attempt to harvest credentials. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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.
  • 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://cicatsalud.com/html/sites/default/files/webform/99368311749.pdf In PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/21030689395.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/47432021317.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/47116150145.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/banofamuwidobekoke.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/tuwagamutavuvefofufeniz.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/bugoxugokerudanetisene.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/rarapenebeku.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/1289321409.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/72246142748.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/42283273604.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=d-link+dir-615+router+login+passwordPDF link annotation
    • https://umatter.princeton.edu/system/files/webform/requests/tutoturabawukaxubudevodor.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/posilo.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/83328436210.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d1dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1DD 5644 bytes
SHA-256: b68ccacb0f0d5f0727e3b638fe2b68a861dcfdef36c5c34fb83a8ecdf2ddfce2
font_01_sfnt_off0000e541.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE541 10436 bytes
SHA-256: 59ca5c2875b20b815805522b62fd2e55d1fb05de87a1593b862fb857223ab99f