Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb8a746a0e30ba09…

MALICIOUS

PDF

70.1 KB Created: 2021-04-20 02:23:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 638bd13015823a63098db47c2b4f5c2f SHA-1: 23f07b41bc11e6a38b1e837894d360524c537d00 SHA-256: fb8a746a0e30ba09a5cf814207a77a3af8ff2a1c1fd9c60af82484ebff723382
126 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. The PDF contains numerous embedded links pointing to various domains, many of which are flagged as disposable hosting, suggesting a link farm designed to obscure the ultimate destination. The document body, though heavily obfuscated, contains references to 'Windows server 2012 r2 activation key crack', reinforcing the phishing lure.

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://www.muttypawsacademy.com/sites/default/files/webform/vaccines/65827293628.pdf In PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/vawutudujenopudup.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/wajuso.pdfIn PDF document text
    • https://www.dgs-interparts.be/sites/default/files/jinez.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/nuwirofu.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/21555212736.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/48103714077.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/dufovomajaxavekasodulep.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/todoxobolukajit.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/fabifuturofutip.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/wafawujozovu.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/~3/3CAf4wW3hvY/uplcv?utm_term=windows+server+2012+r2+activation+key+crackPDF link annotation
    • https://drones.princeton.edu/system/files/webform/61493424170.pdfIn PDF document text
    • https://campusrec.princeton.edu/system/files/webform/luzatebinibaxopititum.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/68272747422.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/rifavuzido.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_off0000d305.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD305 5560 bytes
SHA-256: a3f8b4865799cbe7ce7cd714d5a5958b863b464b7ff31f680088faf0dd72492e
font_01_sfnt_off0000e629.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE629 10900 bytes
SHA-256: 9e0372f5846118c51202d062effef5d5dbd2a0fd50a6127f58bdfad868436bc4