Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a56bfbbb5f23267…

MALICIOUS

PDF

66.2 KB Created: 2021-04-14 15:51:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-30
MD5: 750e33db18b2b24c205f69306fdce0c5 SHA-1: 9359dd0fda9878dd50ae57d67381aa902918fd65 SHA-256: 7a56bfbbb5f23267e16faaa2399b3af28b45b2738d4fa8dcfa52fe1bd552ef90
126 Risk Score

Malware Insights

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

The ML classifier and ClamAV detection strongly indicate maliciousness. The PDF contains numerous embedded URLs, many of which are hosted on domains that appear to be part of a link farm, suggesting a phishing or malware distribution scheme. The document body, though heavily obfuscated, contains references to 'manual' and 'wkhtmltopdf', indicating a potential lure to disguise malicious content.

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://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/4264017636.pdf In PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/92207600326.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/49109440539.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/47545977947.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/95133977644.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/10654010608.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/tatemomolefifepa.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/ranet.pdfIn PDF document text
    • https://architecturaldesigninc.com/sites/default/files/masugikiretige.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/bemefunojupupik.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/kilolegejesap.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/kuvusuwube.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/94808830073.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/DOqCt-cVA4I/uplcv?utm_term=aprilia+shiver+750+gt+manualPDF link annotation
    • https://gradfutures.princeton.edu/system/files/webform/pelafo.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/7842358922.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_off0000c52e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC52E 5628 bytes
SHA-256: ea4f07769fefcae341b1f6701e278c51a63fc09a7493de690202b88c30f15416
font_01_sfnt_off0000d834.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD834 10348 bytes
SHA-256: 432b589217e5fc7d765b0ffbf32a2cc6fc8ccc053d1280f4e55fe493b79170b8