Malicious PDF — malware analysis report

Static analysis result for SHA-256 4158d7b2a3dc2370…

MALICIOUS

PDF

69.8 KB Created: 2021-04-17 08:14:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: a4ee4d2aa97eb54303fbad18d718bd9c SHA-1: fd08bf91e228098c9e76b8f6e14f4af57e175640 SHA-256: 4158d7b2a3dc237021b63204f4cc58b4c90cfd53d180e109ac7bd793f383d282
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to link farms, suggesting an attempt to redirect users to malicious sites. The document body, though heavily obfuscated, contains references to 'Geronimo Stilton TV show episodes' and 'wkhtmltopdf', indicating a lure tactic.

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/58709767715.pdf In PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/238550972.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/32112495638.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/dekif.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/25507329945.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/54125375098.pdfIn PDF document text
    • http://www.birdlifebotswana.org.bw/sites/default/files/webform/sightings-sketches/13349970620.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/zolevijovexoneda.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/31626011693.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/vawutudujenopudup.pdfIn PDF document text
    • http://www.birdlifebotswana.org.bw/sites/default/files/webform/sightings-sketches/12812059159.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/40041164747.pdfIn PDF document text
    • https://www.afscme65.org/system/files/webform/11173368180.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/fzgW7-mxBc0/uplcv?utm_term=geronimo+stilton+tv+show+episodesPDF link annotation
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/sukazejaso.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/54002061309.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/13590028771.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_off0000d13c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD13C 5172 bytes
SHA-256: 4cb6d2bf4170b6ec372dcb4e643eaf19514860ff13ad2fa2a1fdd916a168f37f
font_01_sfnt_off0000e2c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2C1 11536 bytes
SHA-256: e099bd4d9cb745a2756eba84bed6ea9d3dc4478d30823ce69e8f81cd06807044