Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c21d079bb6494e7…

MALICIOUS

PDF

68.6 KB Created: 2021-04-13 22:56:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 8c6d91d366072fee7e4a0579907460b3 SHA-1: e9df53867ab6434fe60c5b43773ae98a96d1cd81 SHA-256: 6c21d079bb6494e729cb6223f836ba0a185ef501bde089d3f618f815c82c4a09
134 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, indicative of a link farm used for phishing. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were directly extracted, the PDF structure and URL patterns align with common phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • AcroForm button with action trigger low PDF_ACROFORM_BUTTON
    PDF contains a /Btn form field together with a SubmitForm/URI/Launch/JS trigger — this is the building block of fake 'Download' or 'Open' button overlays used in PDF phishing lures
  • 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://portal-mysigma.com/system/files/student-proof/wofofokarawivuboniju.pdf In PDF document text
    • https://www.jsif.org/sites/default/files/webform/kedoruxanagavapiwo.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/topijetidilotifoga.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/bekam.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/1289321409.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/vinoku.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/kokibilelage.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/25507329945.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/ralivowu.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/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=the+hellbound+heartPDF link annotation
    • https://community.princeton.edu/system/files/webform/36479690150.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/kabajizonen.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/50075528518.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/56905881998.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/sutuzosugogaw.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/rutepirunumobapof.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/99818817157.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/jidubiziro.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/26360011081.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_off0000d25f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD25F 4824 bytes
SHA-256: fca8528da4c2d0353ad81a4a1c58f433a431499c144696ff74436f4e7b9c493b
font_01_sfnt_off0000e2b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2B5 10220 bytes
SHA-256: 26a48efca5a22f854300494284e285e1074f22f8632cc313d54cc62660949afe