Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1a73b70aebf157c…

MALICIOUS

PDF

69.7 KB Created: 2021-01-12 15:28:39 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 43aab07bd419102a019b62cb354339a0 SHA-1: 7941600c7241fd3759f7230ef9ac35810bf9bd44 SHA-256: a1a73b70aebf157c7e9fc61a83947a1e991ccacebe24cb9b3b09af2a2ae28798
126 Risk Score

Malware Insights

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

This PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded links pointing to external websites, suggesting an attempt to redirect users to malicious content or phishing pages. The document body is heavily obfuscated and unreadable, but the presence of many links and the high detection scores indicate a malicious intent to exploit user interaction.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://trafftec.ru/aws?utm_term=hello+world+android+studio+pdf
    • https://static.s123-cdn-static.com/uploads/4392862/normal_5fdee9ff6d5d9.pdf
    • https://cdn-cms.f-static.net/uploads/4371005/normal_5fc289a1181b2.pdf
    • https://zugufavowi.weebly.com/uploads/1/3/0/8/130874222/1e57d7e35e74196.pdf
    • https://cdn-cms.f-static.net/uploads/4473031/normal_5fc04e58125d4.pdf
    • https://site-1173140.mozfiles.com/files/1173140/misanux.pdf
    • https://site-1175049.mozfiles.com/files/1175049/open_office_spreadsheet_tutorial.pdf
    • https://natizupasa.weebly.com/uploads/1/3/1/4/131437725/1a288a.pdf
    • https://xevosafodom.weebly.com/uploads/1/3/4/7/134739965/9669187.pdf
    • https://site-1175696.mozfiles.com/files/1175696/17002112761.pdf
    • https://bafovulik.weebly.com/uploads/1/3/1/0/131070506/93b36e414b9920e.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/zukogi/android_recyclerview_inside_scrollview_example.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d23d.bin
0dc162f33a3a7270bd319bc286c7c49079b056821aaf09b5af3b91c01f86803c
pdf-font-stream PDF embedded font (sfnt) at offset 0xD23D 5088 bytes
font_01_sfnt_off0000e3a9.bin
d58e7315e3547f049d0faee40233ddc1e54463948a4edb853ca4ec0703d9adad
pdf-font-stream PDF embedded font (sfnt) at offset 0xE3A9 11320 bytes