Malicious PDF — malware analysis report

Static analysis result for SHA-256 cabf8b21f9a84b49…

MALICIOUS

PDF

77.0 KB Created: 2021-04-06 19:15:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 565d8684269168d349d2de66ec0e1840 SHA-1: cc0ecb047695bfaf9ec11bfebdb76ee2a90d99bb SHA-256: cabf8b21f9a84b49f6a1c5a7d0c4bd9752eb3752f2056f22da69d178880903f1
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is a PDF document identified as malicious by ML classifiers and ClamAV. It contains numerous external URIs, many of which point to benign domains, but the overall structure and the presence of a link farm on disposable hosting suggest a phishing or exploit delivery attempt. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the heuristic firings indicate a malicious intent, likely involving exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://www.blplegal.com/sites/default/files/webform/lolavojirubopikumu.pdf In PDF document text
    • https://www.termis.org/system/files/webform/776381217.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/tojawi.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/kobovigub.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
    • https://ambrose.edu/sites/default/files/webform/2306024917.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/bavowusakixonodokuja.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/50818196885.pdfIn PDF document text
    • https://www.mainephilanthropy.org/sites/default/files/5296457674.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/noranixuguwetepefosobad.pdfIn PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/razodogodipuvubetixem.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=pub+and+grill+menu+pdfPDF link annotation
    • https://www.vub.be/sites/vub/files/webform/piwolumubixu.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/9071701793.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_off0000f0d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0D9 5324 bytes
SHA-256: 4360ab790e28e76dd2cea79a2c19fe5f7d7dbb1e2181fa8689a9425c184397f0
font_01_sfnt_off000102e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102E1 10672 bytes
SHA-256: 4ad8c94bd159e08f16f23592d85e3674d92144410eab3223f956baf3bbaa62b8