Malicious PDF — malware analysis report

Static analysis result for SHA-256 31b6ef751087073a…

MALICIOUS

PDF

78.0 KB Created: 2021-09-08 23:28:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-01
MD5: 8a0f77c35e41f3ab7e753c43a6738b8f SHA-1: 517a72f1d2b1554325154c1d014079f9f7bb5d4f SHA-256: 31b6ef751087073a1aef1c6365e9139a3cbba40cce46bbb4dd29390301139b1a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://faresaldabbous.com/uploads/files/fadoxaferosofisud.pdf In PDF document text
    • http://wadsoda.com/UserFiles/File/jetozoselisawofadufonofa.pdfIn PDF document text
    • http://xinyuemu.net/assets/202109/files/20210902192147414489.pdfIn PDF document text
    • https://sogelec-eng.com/files/ckfinder/files/8303923610.pdfIn PDF document text
    • http://techsystem.gr/data/uploads/ckeditor/files/63786465819.pdfIn PDF document text
    • https://client-sms.com/ckfinder/userfiles/files/kosatiketiwenematom.pdfIn PDF document text
    • http://zussobrance.sk/grafika/dokumenty/sedisorenerujibelowo.pdfIn PDF document text
    • http://spostojow.pl/userfiles/file/87036933050.pdfIn PDF document text
    • https://tempatpasang.com/contents/files/7394809357.pdfIn PDF document text
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/18d794d4002909c3980469fcd72da18b/gidemipax.pdfIn PDF document text
    • http://henanshuangxin.com/d/files/59473438345.pdfIn PDF document text
    • https://miguktour.com/FileData/ckfinder/files/20210902_6BA912C844286145.pdfIn PDF document text
    • https://regaluxiluminacion.com/uploads/assets/file/82283349454.pdfIn PDF document text
    • http://shepardinteriordesign.com/rw/upload/file/kalagenugosivukagupuki.pdfIn PDF document text
    • http://adec-interiors.net/Uploads/file/sanexuwidorivenujezidux.pdfIn PDF document text
    • http://i-physiology.ru/upload/fewaxowafolulug.pdfIn PDF document text
    • http://lasermedia.cn/userfiles/file/40742750011.pdfIn PDF document text
    • https://rpaxis.net/userfiles/file/lividiwagozefo.pdfIn PDF document text
    • http://cuspsurgeons.com/userfiles/file/23023482971.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/161304f174bc7e---70567895631.pdfIn PDF document text
    • http://fuguchair.com/upfolder/e/files/20210901092316.pdfIn PDF document text
    • http://phukientubepxinh.info/gomsu/sanpham/anh/files/nosonumarimitonotonu.pdfIn PDF document text
    • http://industra.sk/userfiles/file/koragugukobuziri.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613300a93465e---13276069402.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/ee01590f85fdb0f346718a76137f3633/79888597987.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=seven+mortal+sins+watch+onlinePDF 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_off0000cc47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC47 10720 bytes
SHA-256: d01ad5fb2c0cf97ab61f4f123dc69d6c7d82dfe3c2bafc10a8ed7a8d88b1f263
font_01_sfnt_off0000e4bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4BB 17072 bytes
SHA-256: b35726f8c3b8dbe1c29b1d3844372cfc5c9f8e1a7e749a997823c5c96839f56b
font_02_sfnt_off000110ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110BA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1