Malicious PDF — malware analysis report

Static analysis result for SHA-256 6937957b969a063f…

MALICIOUS

PDF

70.2 KB Created: 2021-04-25 06:31:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 962e3d59d5b595d3557afdbbd2e90c21 SHA-1: 8f6eebab5c55d4bdfabc0e2033f8c2c2fc10e565 SHA-256: 6937957b969a063f20628eff625622b95fd5aa9dcd75a2392c14ab0ba8571d16
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some of which are hosted on disposable domains. The document body, though heavily obfuscated, contains references to 'correspondence courses army 2018' and application metadata, suggesting a lure for potentially sensitive information or further exploitation.

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 https://www.pharoxglobal.com/sites/default/files/webform/garuwofewitenobakufenewi.pdf In PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/vewamilobofesiwukor.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/pexutagizoniged.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/nuxikovevevugodir.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/30106672217.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/61975266633.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/woluweweketasuzizolog.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/70645978292.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/97818084314.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/Om9ozkHLxGw/uplcv?utm_term=how+to+max+correspondence+courses+army+2018PDF link annotation
    • https://drones.princeton.edu/system/files/webform/voretazejujuwewoz.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_off0000d242.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD242 5932 bytes
SHA-256: 577de3208246925fb23ffb9cdc3a3f0b06e5a99d096886683667256269c6ba94
font_01_sfnt_off0000e673.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE673 11104 bytes
SHA-256: 81a9c05b1506038844cb2de6488d01f068a098bbc24e10dd652c102bf7e894ce