Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8e57446aa0ee171…

MALICIOUS

PDF

78.5 KB Created: 2021-04-07 10:06:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: f042fd110927f78bf14f16f3dcff5bac SHA-1: 3547451fc34f3232b036059a309b3b1053c2e699 SHA-256: b8e57446aa0ee17153199b498d7a3eb6d47cd064c5ae84a45888757391915cb3
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

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.osgeurope.com/sites/osg-corporate.dev/files/webform/19824824677.pdf In PDF document text
    • https://ambrose.edu/sites/default/files/webform/42416127327.pdfIn PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/loboje.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/monufugabezexi.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/vogelunejubujapezidugave.pdfIn PDF document text
    • https://natsihwa.org.au/sites/default/files/webform/filon.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/80982398497.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/54003515034.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/PmAiG5ZyT-k/uplcv?utm_term=paradisus+punta+cana+map+pdfPDF link annotation
    • https://gradfutures.princeton.edu/system/files/webform/42179508969.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_off0000f5ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5EA 5272 bytes
SHA-256: 817af23bbf278072fcbe357ba3456ea9738f4597b0f13f3ff365e22f66ca29bd
font_01_sfnt_off000107c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107C4 11304 bytes
SHA-256: 9dc5e8906c7c3e9e44160be5d30956dfdffa384cbfd17f6685e476fe2f713af5