Malicious PDF — malware analysis report

Static analysis result for SHA-256 7583d4781099d7d9…

MALICIOUS

PDF

66.2 KB Created: 2021-04-22 20:45:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 7cc5de7990f1cfe9045554869cbc85a9 SHA-1: 9d5f968567aca6cfbc06f60d60090c805372c99c SHA-256: 7583d4781099d7d9578c08ebdbd5d157c5d9ec134fbdfa86bfb3cf683cbbcf34
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ML and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable or unknown domains, suggesting a link farm designed to redirect users. The document body is heavily obfuscated and appears to be junk data, further indicating a malicious intent rather than legitimate 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://www.natsihwa.org.au/sites/default/files/webform/tuwagamutavuvefofufeniz.pdf In PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/65810703597.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/gegemapoxazokex.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/41850888982.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/42535902170.pdfIn PDF document text
    • https://natsihwa.org.au/sites/default/files/webform/46250275999.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/pifudolaloxafedotodela.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/97818084314.pdfIn PDF document text
    • https://www.visitsavannah.com/sites/default/files/webform/fukixuliwidopisoduzurapi.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/~3/1xuhb7AK25c/uplcv?utm_term=dark+souls+wikidot+sorceriesPDF link annotation
    • https://umatter.princeton.edu/system/files/webform/requests/72435273025.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/85824103047.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/98562832035.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/27560642257.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_off0000c707.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC707 5088 bytes
SHA-256: b637a47d9437f3250838004172e1801de62ee1282c473d8e2355e5fab18fa6f7
font_01_sfnt_off0000d87f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD87F 10424 bytes
SHA-256: dcfeb3fdf81b64275cb02c4284004fd907056c9b25d76bba2cceb97395a4bbe2