Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d03166e4926dcd0…

MALICIOUS

PDF

70.8 KB Created: 2021-04-16 00:59:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 2c752abd76bf289af554bfdd526eca90 SHA-1: 5bfcb0e66c091a150a6fc4708487bdba6b2f65cc SHA-256: 4d03166e4926dcd0d7cc8a0eb8c6aa1029a443164fec57e12dd387fceace281a
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 disposable domains or are structured as link farms, as indicated by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the nature of the embedded links and the PDF structure points towards an attempt to redirect users to malicious content.

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 http://cicatsalud.com/html/sites/default/files/webform/99284441703.pdf In PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/fezijorimofilafomifum.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/setafemamuf.pdfIn PDF document text
    • https://www.afscme65.org/system/files/webform/rerezuduzolorefa.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/fifomibap.pdfIn PDF document text
    • https://www.afscme65.org/system/files/webform/tikat.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/wafawujozovu.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/72246142748.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/kepasibadugemefobovabo.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/zozagosetimof.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/46846662681.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/tatemomolefifepa.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/mibotemesasis.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/sidetarebuw.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/30199048500.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/~3/1KS0DP0cxss/uplcv?utm_term=aspirin+lifestyle+bookstore+menuPDF link annotation
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/68876097481.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/xegenaxug.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/juvuwudonuvusenovirem.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/wijudabopijobomoxusosul.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_off0000d728.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD728 5132 bytes
SHA-256: d112e29d2ea033ae22a4340c20e27a0ced8c5b133a489f7532f29d399b30e4b0
font_01_sfnt_off0000e897.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE897 10512 bytes
SHA-256: 0b38a06ef90965178c113cd460bd4f6f69924f36592cd1d27ec3532d6a34b8f0