Malicious PDF — malware analysis report

Static analysis result for SHA-256 50ecc7a57c631505…

MALICIOUS

PDF

76.2 KB Created: 2021-04-10 13:47:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: efaec96ed5c5c203e6392dbfdab0d284 SHA-1: 50d2f160c1bd241a68e204dc9b16b4e080c86ec0 SHA-256: 50ecc7a57c6315053e07836e047514d74a7836f4c282fb6d3650d6448e295386
126 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it is a link farm on disposable hosting. Although no scripts were explicitly extracted, the PDF structure and embedded URLs suggest an attempt to redirect users to potentially malicious sites. The document body, though heavily obfuscated, contains text related to sheet music, serving as a 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 https://www.dgs-interparts.be/sites/default/files/41094691834.pdf In PDF document text
    • https://ambrose.edu/sites/default/files/webform/71027525942.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/mimixinaxeralowevowijut.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/86303695333.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/ginigiwosumomigari.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/90077644064.pdfIn PDF document text
    • https://www.jts.org.jo/sites/default/files/webform/86196288468.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/mulakipezumaxusilexuvu.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/58234525485.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/48232920683.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/238550972.pdfIn PDF document text
    • https://www.afscme65.org/system/files/webform/baxuwobokorexifiri.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/zavemazawutojene.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/95374483905.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/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=ascent+day+1+ludovico+einaudi+sheet+musicPDF link annotation
    • https://thesanfordschool.asu.edu/sites/default/files/webform/99818817157.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_off0000e867.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE867 5288 bytes
SHA-256: e037f566c290b902a366bdc47552e20015f61049122b0d7dea159065fc50e5b3
font_01_sfnt_off0000fa4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA4F 12232 bytes
SHA-256: b48c5aaa041d14d9da504881e2d1bf1fcee6ac602ad0c96371e467b7c41cbe6c