Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b75918342208c93…

MALICIOUS

PDF

70.7 KB Created: 2021-04-09 10:06:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: edecb20a46d51cb1ed5e0c0869e877a4 SHA-1: af648fcb2bf195661e27987d35f98088ea0872c6 SHA-256: 4b75918342208c93c4390115c3b7f5d640afed36a3873ee5b070adff5ecfb852
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The document body, though heavily obfuscated, suggests a lure related to 'Altium designer 10 tutorial pdf'. The presence of numerous embedded URLs, many pointing to disposable domains or link farms, further supports a phishing or malware distribution scheme. No scripts were extracted, but the overall structure and heuristic firings strongly suggest this PDF is designed to trick users into downloading a malicious payload.

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 http://oaklandchildcare.org/sites/default/files/webform/41266633523.pdf In PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/48862039041.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/taxevoxasubosiwugudabi.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/lavajaruzapelusudixavu.pdfIn PDF document text
    • https://www.dgs-interparts.be/sites/default/files/bipaxuvimul.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/8474239295.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/ziseriwutekezarog.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/wajuso.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/80411930416.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/vojazasazobixupolaxi.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/84972388600.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/futexapepunuvanujom.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/47965191786.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/1232685222.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/81254010544.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/YTWXjIUwRh0/uplcv?utm_term=altium+designer+10+tutorial+pdfPDF link annotation
    • 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_off0000d5e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5E7 5544 bytes
SHA-256: 40f99003ed605afdb9cf91b01145d31d481a70c9ed24aeb028dbebc6338909a4
font_01_sfnt_off0000e8b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8B4 10876 bytes
SHA-256: a525c817451b3a8c20a949fde50b71d1075d889187f7d9f5066badb558965be8