Malicious PDF — malware analysis report

Static analysis result for SHA-256 c87a7c04812c3670…

MALICIOUS

PDF

73.3 KB Created: 2021-04-13 01:58:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 92f2056eca0301befd3c6d7dea5092b7 SHA-1: 7d3bb2921d874ecf760189f14e03c2a6dfa469d4 SHA-256: c87a7c04812c367018682a567367d4a1b6bd7cebe1262a2b4d987d6e1f133e13
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to unknown or potentially malicious domains, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are consistent with techniques used to redirect users to malicious sites, often as part of a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/ziseriwutekezarog.pdf In PDF document text
    • https://www.jsif.org/sites/default/files/webform/meratasadif.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/31843799141.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/27880179426.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/susumijifiwef.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/xubapubawaral.pdfIn PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/wavunivuzabanovomid.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/85278691340.pdfIn PDF document text
    • https://natsihwa.org.au/sites/default/files/webform/17015803.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/9027254294.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/vonasajevevedatenalezeb.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/cv9VXjIrmdE/uplcv?utm_term=itextsharp+pdf+to+htmlPDF link annotation
    • https://minorsoncampus.princeton.edu/system/files/webform/janoruzafasolefixos.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/mizol.pdfIn PDF document text
    • https://campusrec.princeton.edu/system/files/webform/popikinof.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/61493424170.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/16157352895.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_off0000e18e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE18E 5288 bytes
SHA-256: c6a11ee6aa33e69a9faaa40f5dc9fc3563ee3b008f13c52e910ae9fe2578f7ca
font_01_sfnt_off0000f368.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF368 10964 bytes
SHA-256: e99c37c277f04a9b02d6db38307ff23e4f44065823552814fdfa2ccbe56d1689