Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a16d4a4edaed2fd…

MALICIOUS

PDF

77.3 KB Created: 2021-04-06 23:35:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 4e6837a370800c3423d40a462b466cee SHA-1: 75b4c8a2949768125a899d3548b53e9a44a7d9ec SHA-256: 5a16d4a4edaed2fdb63b9947c5c0386f53d1cdaf0b81960bec1fbfe773e70c99
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to disposable domains, suggesting a link farm or phishing attempt. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URIs are consistent with techniques used to redirect users to malicious sites, likely for credential harvesting or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://www.natsihwa.org.au/sites/default/files/webform/42406093886.pdf In PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/95133977644.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/28911573484.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/sakobonomoduriv.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/mitiporaju.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/80411930416.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/17184396690.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/6659556688.pdfIn PDF document text
    • https://www.mainephilanthropy.org/sites/default/files/79141676299.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/40307308503.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/65047245793.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=insertion+sort+pseudocode+pdfPDF link annotation
    • https://lib.asu.edu/system/files/webform/bidemuf.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/68876097481.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_off0000e5e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5E0 4844 bytes
SHA-256: b2024dbc11aec256b64a8a08ba7f7ef62724145258e9a8063fd0afd8b8f2f4d0
font_01_sfnt_off0000f668.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF668 1800 bytes
SHA-256: 51ebeec29509b87aa858d500e37ac8853184703d07d1f913ce36d8e1dc7764c0
font_02_sfnt_off0000fef6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEF6 12356 bytes
SHA-256: 963d7cb682930f2dd85964ca026a3aed411cbbf58188ad7b81ba7f39554f8c0f