Malicious PDF — malware analysis report

Static analysis result for SHA-256 3ac20de70ad40bb0…

MALICIOUS

PDF

79.2 KB Created: 2021-04-10 21:20:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 077f189f08c0937b051ebbff5db92793 SHA-1: 159571eef133ffcf9d7fafa459f4e5f587cfbba0 SHA-256: 3ac20de70ad40bb003c91ad6e003dbd94f56807cbe7ce030fce674cec0e6b16b
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 heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document is part of a link farm designed to host malicious content. While no scripts were explicitly extracted, the presence of embedded URLs and the overall structure point towards a phishing or malware distribution attempt, likely using a social engineering lure disguised as an instruction manual.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.pharoxglobal.com/sites/default/files/webform/70645978292.pdf In PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/72246142748.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/13178745316.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/zabufenopi.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/77861868930.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/jevosofotabotasif.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/69309865186.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/LPIa9PGmDLg/uplcv?utm_term=stihl+ts+700+instruction+manualPDF link annotation
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/68876097481.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/tujuxegagisezemesolut.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/ludazerubadariwevulefaxu.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/kuwidiloj.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/wijudabopijobomoxusosul.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/libovonudipiguriteg.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA6B 2960 bytes
SHA-256: 4c688c0676da4c9c3f1d636d29496b85ed1f90b4285ee9b780884cc7de0e34ac
font_01_sfnt_off0000f4db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4DB 5364 bytes
SHA-256: fc1ce7cdebde79f6d8ae7ccd0979b203e32a3b2c3a1e36259eba802a99314871
font_02_sfnt_off000106ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106EC 11960 bytes
SHA-256: 72a9194cd9e2240951cef5c87610e49c76b4c2d6948ab711091f477553c74b6e