Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5f0c74c09cfd8b6…

MALICIOUS

PDF

75.3 KB Created: 2021-04-10 18:44:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: 4d7e0624fd72b073550a56b97e60b5c8 SHA-1: 57f8dc7b0f6c96d7f6b0d8d51914776846db32b5 SHA-256: d5f0c74c09cfd8b68ceb36ce38693a638d9bc8e2ccdbf6bbfc4d442dc71f5bdf
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The document body contains obfuscated text and references to "Troll face text", suggesting a lure. The presence of numerous embedded URLs, many pointing to potentially compromised legitimate domains, indicates a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it is designed to exploit vulnerabilities or redirect users to malicious sites.

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://ambrose.edu/sites/default/files/webform/kubuxodadiwozubak.pdf In PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/25507329945.pdfIn PDF document text
    • https://architecturaldesigninc.com/sites/default/files/36110977311.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/34782296767.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/bekam.pdfIn PDF document text
    • https://www.mainephilanthropy.org/sites/default/files/guvobirewuge.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/sabaw.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/joxelivoresilawefuxeli.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/17654710786.pdfIn PDF document text
    • https://www.viachristi.org/sites/default/files/webform/89070061484.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/19824170549.pdfIn PDF document text
    • https://www.visitsavannah.com/sites/default/files/webform/nodarinit.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/palepipob.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/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=troll+face+textPDF link annotation
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/46273532178.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_off0000e894.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE894 4716 bytes
SHA-256: b891c7a5ea89babdb3f4d3d572ac2bc672b64dd7fa7d1860203e23304b6af8d2
font_01_sfnt_off0000f8ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8AD 12588 bytes
SHA-256: 0dcc76c292e96416dc8f234d71d4e11a89c97334784512bf98e0397c33707869