Malicious PDF — malware analysis report

Static analysis result for SHA-256 f71f3d6cfb353da8…

MALICIOUS

PDF

67.9 KB Created: 2021-04-22 05:12:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: 6f15bdd383b7394b44af6007efa55c1c SHA-1: f4095c9a3f0113fba418ad68ca83c5aed53477e6 SHA-256: f71f3d6cfb353da8371f1403fa01fc150bb384eefbe92ca84addebf503f0bf93
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with several pointing to potentially malicious domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a malicious document, possibly leveraging JavaScript for exploitation.

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://cicatsalud.com/html/sites/default/files/webform/sidetarebuw.pdf In PDF document text
    • https://www.termis.org/system/files/webform/776381217.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/54125375098.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/54003515034.pdfIn PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/wokasonexigugeb.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/pagasumoxozodaxatukaliwus.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/wafawujozovu.pdfIn PDF document text
    • https://www.dgs-interparts.be/sites/default/files/42042694998.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/cv9VXjIrmdE/uplcv?utm_term=burger+king+breakfast+timePDF link annotation
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/8342566550.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/luzixuganigofifabeja.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/pagilavamuvawasaxega.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/xafuzekimizitigemuseli.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/46247033309.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/42655509772.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_off0000cc2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC2C 5308 bytes
SHA-256: d7134f2846b6ddbf90c9ecb2568cbfb482c975552b42917c15277d8f4eb71715
font_01_sfnt_off0000de34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE34 10156 bytes
SHA-256: 274a201f43c4b8bd167a95734f85d77e09c85f12366e36266872674712b921c5