Malicious PDF — malware analysis report

Static analysis result for SHA-256 dbc04f5906bc1bc8…

MALICIOUS

PDF

70.6 KB Created: 2021-04-25 08:49:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 21151db989980886e7819b31de0a5728 SHA-1: 5dbbe1fbb1755342a75af8eba4f5f67c508f45e6 SHA-256: dbc04f5906bc1bc86763268d1cc02e36dbdee0d0e0b2eae70a2e11af9754f277
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, and is flagged by heuristics as a link farm and a phishing/malicious PDF. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and URL patterns suggest it's designed to redirect users to potentially harmful sites, aligning with spearphishing tactics.

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/xexazud.pdf In PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/dojoxopanikofogenag.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/kokibilelage.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/xugapovapoz.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/bavowusakixonodokuja.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/80628544521.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/juremetepatofuf.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/30106672217.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/99469138220.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/tinijozude.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/94808830073.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/54125375098.pdfIn PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/jalipoxelelikepobolid.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/S30rS-6n6vg/uplcv?utm_term=el+pollo+loco+chicken+avocado+taco+nutritionPDF link annotation
    • https://lib.asu.edu/system/files/webform/delibenapu.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_off0000d970.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD970 5064 bytes
SHA-256: d30e6cb2bc38203ef0c3a659d91b2a5393d4eae744cecb8216664ff2e3dcb6c0
font_01_sfnt_off0000eaaa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAAA 10188 bytes
SHA-256: 81cbc35469d503e35f6603d2101a1590b4f71600ed8ea8a8b0aa6008885f9c3d