Malicious PDF — malware analysis report

Static analysis result for SHA-256 b877373d1799c0c0…

MALICIOUS

PDF

89.6 KB Created: 2021-09-14 12:09:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 2085aa8e30f152e8ca483c91d827cbf1 SHA-1: 522782388f58ad6b404520ac3c100000e7ceb703 SHA-256: b877373d1799c0c027aec4bf9a5d63c16013d900ba51fbfb27698ae07e30e7cd
142 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. It also includes numerous external links, many pointing to PDF files hosted on potentially disposable domains, suggesting a link farm or redirection mechanism. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://rama-sp.com/rama/webroot/js/ckfinder/userfiles/files/wivipivagodururirumibap.pdf In PDF document text
    • https://sssmri.com/ckfinder/userfiles/files/nifuwemijakikitow.pdfIn PDF document text
    • http://phamtrangia.com/upload/files/20186204902.pdfIn PDF document text
    • https://piphoto.tw/uploads/files/202109031916301638.pdfIn PDF document text
    • https://livbiopharma.com/userfiles/file/14649626510.pdfIn PDF document text
    • http://naosgym.com/userfiles/files/86223799747.pdfIn PDF document text
    • http://aibasylhet.edu.bd/app/webroot/ckfinder/userfiles/files/94748616920.pdfIn PDF document text
    • http://awarelaxcentrum.cz/user_files/file/18324715123.pdfIn PDF document text
    • http://iccjsc.com/images/uploads/files/70762231007.pdfIn PDF document text
    • http://soles2walk.cz/data/file/jipusu.pdfIn PDF document text
    • https://greshamgilessalon.com/wp-content/plugins/super-forms/uploads/php/files/a2cfefd5cee83b777c99ee6910dcdf7d/52881522097.pdfIn PDF document text
    • http://harrodsrentacar.com/public_html/userfiles/file/57749772942.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/b2hqmrrmh86h8rg7b94l87dli2/fedifelejanadun.pdfIn PDF document text
    • https://www.tzounakos-insurance.gr/ckfinder/userfiles/files/gifobimagisemi.pdfIn PDF document text
    • http://word.mn/uploads/assets/72748926427.pdfIn PDF document text
    • http://progettocecinacuore.it/writable/public/userfiles/file/vuzowawasatimerunetizuw.pdfIn PDF document text
    • http://lungshingcentre.com/userfiles/zezumek.pdfIn PDF document text
    • http://hqshop24.com/userfiles/file/90782374193.pdfIn PDF document text
    • https://thehouseconcert.com/ckfinder/userfiles/files/91794189419.pdfIn PDF document text
    • http://sushiyaslo.com/uploads/files/fizedisuvu.pdfIn PDF document text
    • http://victoryelectricalsupply.com/ckfinder/userfiles/files/64396815109.pdfIn PDF document text
    • http://wine-paraphernalia.com/files/winep/_repo/file/zufel.pdfIn PDF document text
    • http://broadviewlibrary.org/uploaded_bvlib/file/pokojifibofemiv.pdfIn PDF document text
    • http://www.kizkulesikizogrenciyurdu.com/public/ckfinderuploads/files/19657411258.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=the+tutorial+on+excel+macros+vba+pdf+free+downloadPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f75b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF75B 17756 bytes
SHA-256: b128a4735ef96a1e7402ac4bb25f09a347f8f89d03c4db664b568900272c4ec7
font_01_sfnt_off000125c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125C9 11340 bytes
SHA-256: b9081186b3f226e5e6a7084a9ec69d6ffb1ae1df4c6525372e6af715e7825b07
font_02_sfnt_off00014023.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14023 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1