Malicious PDF — malware analysis report

Static analysis result for SHA-256 25883ccd87563240…

MALICIOUS

PDF

80.8 KB Created: 2021-09-21 00:55:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6e11f5ae932520f4fe2e1a9af3fe9572 SHA-1: 0194e0c2c5ec2f338a4b2c52a80f7f57aed75c30 SHA-256: 25883ccd8756324042f65b78f676962d4a96ccb5c58865ee67374d8f5e05d133
126 Risk Score

Malware Insights

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

The sample was flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, many of which point to PDF files hosted on various domains, suggesting a link farm or content distribution network. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly indicates this malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 http://englandmatchshirts.com/assets/file/5150006272.pdf In PDF document text
    • http://nrgmedia.hu/files/file/89039809370.pdfIn PDF document text
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/tekarazarolanomokasepe.pdfIn PDF document text
    • http://lixupeng.com/uploads/files/pozazepowebawix.pdfIn PDF document text
    • http://195exim.com/datas/files/duxajobopitebititubu.pdfIn PDF document text
    • http://mtkshop.com/images/uploads/file/fiwelebaveferawegeb.pdfIn PDF document text
    • http://jezirka-biobazeny.cz/UserFiles/File/xepuko.pdfIn PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/f05bd0dc3e7604bb1c1a7a93019cdf6e/58372823189.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/1613994a531f20---5744120573.pdfIn PDF document text
    • http://www.kroonzuivel.nl/ckfinder/userfiles/files/nelijaxofikuf.pdfIn PDF document text
    • http://bancodevida.com/bancodevida/admin/images/image/file/15247191727.pdfIn PDF document text
    • https://ladangmimpi2.com/contents/files/nosijelupazelapo.pdfIn PDF document text
    • http://104408017.linker.tw/files/jolixebawuwowamobapapow.pdfIn PDF document text
    • https://saikekanglun.com/filespath/files/20210901175944.pdfIn PDF document text
    • http://webcertain.asia/contentupload/fckeditorUploads/organization_/file/nobixinorelemefusi.pdfIn PDF document text
    • http://watdoenwevandaag.nl/upload/28589214596.pdfIn PDF document text
    • http://permagnet.com/upload_files/file/21091213495369822350bjpi.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/fuvinazipewefit.pdfIn PDF document text
    • https://sabagdasarov.ru/upload/file/makogiporipafapi.pdfIn PDF document text
    • http://nitexprofi.cz/userfiles/file/17589842021.pdfIn PDF document text
    • https://www.koreayokogawa.com/ckfinder/userfiles/files/1502096711.pdfIn PDF document text
    • http://sanarina-coaching.de/ckfinder/userfiles/files/gazolebemesal.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=normal+distribution+curve+standard+deviationPDF 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_off0000d633.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD633 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE4A 10816 bytes
SHA-256: e06f9cfe2318c6a6abc85efc0a279629c43a595381b3a0aee4f4a59e418249a2
font_02_sfnt_off00010736.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10736 18152 bytes
SHA-256: e48d313be5f6da7cdb4a4f0bd11407fb0689c5d515ed7edcf3ed6af08c8ac761