Malicious PDF — malware analysis report

Static analysis result for SHA-256 517193befc75a1d8…

MALICIOUS

PDF

76.4 KB Created: 2021-04-08 20:55:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 7d7cff3f5110bcd73de07bfdcbf983c6 SHA-1: 0574d10f9fba5dfb8f79a4ff0f6b3661886ceeff SHA-256: 517193befc75a1d82dcd21eab0ff6c76595872c1fdab31db158aeac952c6fb5e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The document body, though heavily obfuscated, contains text suggesting a lure for a 'Haematology book pdf download'. The presence of numerous external URIs, many pointing to disposable domains or link farms, further supports a phishing or malicious content distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.mothercare.ro/sites/default/files/webform/resumes/tawapiseligimagawawujimo.pdf In PDF document text
    • https://www.dgs-interparts.be/sites/default/files/42042694998.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/4264017636.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/zomosazufexebale.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/65047245793.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/38059385999.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/xexazud.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/memirudomonejusowanasu.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/95216779236.pdfIn PDF document text
    • https://europa-ts.ru/sites/default/files/webform/6529842099.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/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=haematology+book+pdf+downloadPDF link annotation
    • https://drones.princeton.edu/system/files/webform/66931006591.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_off0000ea21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA21 5444 bytes
SHA-256: 276085cd831ef651ed28191ea0a9d307e8a0f6273cd83cace386941ed0832b4c
font_01_sfnt_off0000fcb2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCB2 11832 bytes
SHA-256: 0950095ae31e4f868a3f7d46979adf6833012e6d3a37ca13e53a8f23a0727e2e