Malicious PDF — malware analysis report

Static analysis result for SHA-256 78ecd3f8a8444aa9…

MALICIOUS

PDF

67.5 KB Created: 2021-04-22 04:09:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 07315437d19607c6a3e5a3e00fa1f493 SHA-1: 7b24c2127bd6f1387575568c8c59586f23e318c7 SHA-256: 78ecd3f8a8444aa9ff010f26b7203e22c7bdb70472ebbe2eb6e345ddbdb6e507
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. The document contains numerous embedded URLs, many pointing to disposable domains, which is characteristic of link farms used for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and the presence of many external links suggest an attempt to redirect the user to malicious content.

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://europa-ts.ru/sites/default/files/webform/81905598419.pdf In PDF document text
    • https://ambrose.edu/sites/default/files/webform/99544266771.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/85278691340.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/3563422068.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/66271497470.pdfIn PDF document text
    • https://www.woonsocketri.org/system/temporary/webform/kebadewanizokodijixupid.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/27017481005.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/wogudodijanaferewinige.pdfIn PDF document text
    • https://europa-ts.ru/sites/default/files/webform/sujeludepotunebimetoravij.pdfIn PDF document text
    • https://www.jts.org.jo/sites/default/files/webform/96043924660.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/13471650610.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/28693943460.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/GLLx1DTH0VQ/uplcv?utm_term=hunter+fan+remote+control+troubleshootingPDF link annotation
    • https://gradfutures.princeton.edu/system/files/webform/42179508969.pdfIn PDF document text
    • https://campusrec.princeton.edu/system/files/webform/26909318775.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_off0000cc05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC05 5396 bytes
SHA-256: 651d71c33f78a93043f5e29b592b6727c65f876aa83d76507015622b975367a6
font_01_sfnt_off0000de33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE33 10284 bytes
SHA-256: 40122f27b24e90bdd65a231cdf0183b204ac5ecfd942f169f6a3d17ee330e46e