Malicious PDF — malware analysis report

Static analysis result for SHA-256 6164b5fd6e479f6e…

MALICIOUS

PDF

76.4 KB Created: 2021-07-24 14:03:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f4130905fbf2ac9aa9be5c7d48d94f48 SHA-1: ac77f88bec83897b15949efb499454fd9b8e1540 SHA-256: 6164b5fd6e479f6ea72297b3dab4e49ce27431f5b6df7d74585dfe5d758bcd18
96 Risk Score

Malware Insights

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

The PDF file was flagged by an ML classifier as malicious and contains numerous embedded URLs. Several heuristics indicate it functions as a link farm, with many links pointing to compromised WordPress sites or disposable hosting. The primary purpose appears to be directing users to external, potentially malicious, websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 5

  • 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 http://saigondome.com/uploads/userfiles/file/48427888839.pdf
    • http://thienlongadv.com/upload/files/lasuted.pdf
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e54278a33a9---60504724356.pdf
    • http://minhanh.com/files/2276885407.pdf
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16088533f428e5---23588650695.pdf
    • https://ludifrance.fr/userfiles/file/57531235690.pdf
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/70983a805ceb27164c99662f8ac8fe66/75231793232.pdf
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/2bb50d61c8c7d2e2de345a99f325c762/kuvuxugoxudedidekomaf.pdf
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/61a1b5271ae4f6768f3836b6d9c6bf9f/80643048083.pdf
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609daef880a22---fivofavuluxi.pdf
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160839f1a0f516---bebajovepolujumov.pdf
    • https://e-lightingcontrols.com/wp-content/plugins/super-forms/uploads/php/files/af8ec56c2ff2791eda90d1ed40b1f589/28552784495.pdf
    • https://mk-promotions.com/ckfinder/userfiles/files/24037579991.pdf
    • http://baigeleather.com/userfiles/file/54969611001.pdf
    • https://andymullinscommercial.com/home/andy/public_html/ckfinder/userfiles/files/59362313800.pdf
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160805cc17ee7e---suzapabusafagibutupapi.pdf
    • http://circuitvietnamcambodge.com/hinhanh/file/jumomupefux.pdf
    • http://autobedrijvenindex.nl/images/uploads/nubenetepiroruxexose.pdf
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ebe86b7edf---90441414837.pdf
    • https://livre-art.com/ckfinder/userfiles/files/dawolape.pdf
    • https://www.tahitotfalu.hu/ckfinder/userfiles/files/jokudexuno.pdf
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16083e43e93b25---5007897052.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=john+deere+110+lawn+tractor+parts+diagram
    • 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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c637.bin
2bc4d46fbcb0f98e7d9cb6a662a6b09aaf5e60a859ea71fc5ca5dc70095f7054
pdf-font-stream PDF embedded font (sfnt) at offset 0xC637 16576 bytes
font_01_sfnt_off0000f19b.bin
1618e42c703d5056f1335569109351aeacdc1636336ac1f9ad42722ef766fdfb
pdf-font-stream PDF embedded font (sfnt) at offset 0xF19B 11212 bytes
font_02_sfnt_off00010b91.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B91 16792 bytes