Malicious PDF — malware analysis report

Static analysis result for SHA-256 6ac31d53a4dae64c…

MALICIOUS

PDF

68.1 KB Created: 2021-04-10 14:20:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 00fbe8ba8414e88a74ce9b342695bc69 SHA-1: f7107396ff84d7618ae83779b6f1e2f98b2b1354 SHA-256: 6ac31d53a4dae64c09ede386f2820a389d382838ef34a228c72cf610fefc76df
126 Risk Score

Malware Insights

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

The PDF document exhibits characteristics of a phishing or malware distribution lure, as indicated by the high number of embedded external links, many pointing to potentially compromised or disposable domains. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9816

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://ambrose.edu/sites/default/files/webform/nakevatekiviva.pdf
    • http://cicatsalud.com/html/sites/default/files/webform/65000750087.pdf
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/pidefukil.pdf
    • https://www.natsihwa.org.au/sites/default/files/webform/bukitonixoravutewoluba.pdf
    • https://ambrose.edu/sites/default/files/webform/kepasibadugemefobovabo.pdf
    • http://seiary.com/sites/default/files/webform/rec/47545977947.pdf
    • https://www.natsihwa.org.au/sites/default/files/webform/tuwagamutavuvefofufeniz.pdf
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/22206840813.pdf
    • https://architecturaldesigninc.com/sites/default/files/vudezuluxi.pdf
    • https://natsihwa.org.au/sites/default/files/webform/80931084074.pdf
    • https://www.dgs-interparts.be/sites/default/files/muvok.pdf
    • https://www.visitsavannah.com/sites/default/files/webform/59391310887.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=enfoque+mixto+segun+autores
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/wosevojowavinojefe.pdf
    • https://thesanfordschool.asu.edu/sites/default/files/webform/31460711967.pdf
    • https://www.vub.be/sites/vub/files/webform/pagilavamuvawasaxega.pdf
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d330.bin
df087f2fb3685e62896c8a31cb8ed16451c54bebff1e50991297903387d04410
pdf-font-stream PDF embedded font (sfnt) at offset 0xD330 5208 bytes
font_01_sfnt_off0000e4db.bin
c71a2772e844d6b7f38dc84913db63917d0f2958fd01abdc2fdf13e7cd97024d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4DB 11576 bytes