Malicious PDF — malware analysis report

Static analysis result for SHA-256 c7861431333c5cfe…

MALICIOUS

PDF

66.6 KB Created: 2021-04-18 01:48:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: beb3055ecdd95bebe6de703698a747ed SHA-1: b42ac27b285072d11296111911c52f2fff6a833a SHA-256: c7861431333c5cfe2bebdd2cae16be7437a0dd6ca0509cd804bdb810c3d60364
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating it is likely a phishing or scam document. It contains numerous external links, many pointing to disposable domains, suggesting a link farm used to obscure the true destination or spread malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's designed to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://oaklandchildcare.org/sites/default/files/webform/80411930416.pdf In PDF document text
    • https://architecturaldesigninc.com/sites/default/files/masugikiretige.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/wajuso.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/58588935603.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/nuxikovevevugodir.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/38059385999.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/54250685962.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/monufugabezexi.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/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=how+do+they+do+an+echocardiogramPDF link annotation
    • https://gradfutures.princeton.edu/system/files/webform/ninavixokamorul.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/31460711967.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_off0000c9a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9A0 5296 bytes
SHA-256: fe13b6939005814a5fe02fc0d79e9b051e388dfaa706c5765390460f36ba1f7f
font_01_sfnt_off0000db90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB90 10224 bytes
SHA-256: 83584234d33c0fa13633732f6e1c9b961d27133c32f6c5bcdcafdd8c109fb8a9