Malicious PDF — malware analysis report

Static analysis result for SHA-256 421e73c609c1f16b…

MALICIOUS

PDF

68.9 KB Created: 2021-05-06 03:47:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e7568071227206de868532be4b330fd6 SHA-1: 57fbef78345875bfcffa87c7eb9bc53887c59309 SHA-256: 421e73c609c1f16b53c6aa0b8bd0bcd03d44fd34e9c2b8fdee8e84851e43869a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites acting as hosting for other PDF files. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of multiple distinct hosts and the structure suggest a link farm designed to obscure the ultimate destination or to spread malicious content across various compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d820138ef2---vilujobu.pdf
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ab390bc93a---52702909953.pdf
    • https://hotelristorantenovecento.it/wp-content/plugins/super-forms/uploads/php/files/708c5d37acc4b3efbf65134c6ef380d2/zosemigidadinotis.pdf
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/160721e99c1fb6---53089661512.pdf
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089caf2d5795---41963181656.pdf
    • http://aksaaydinlatma.com/img/editor/image/file/71956278239.pdf
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fc7acc92de---39612259560.pdf
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160890b8723226---relanare.pdf
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/bec2aefbb969afe323a6bbf378dedc2b/50446599940.pdf
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1606fe0152d8f0---28470475394.pdf
    • https://srp-galabau-rostock.de/wp-content/plugins/super-forms/uploads/php/files/bb2ntghslanf3f5s6fileeh3p5/xenexopefif.pdf
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/160815e7f7ca5b---lamivuwaxoduzifu.pdf
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce700046dd---vegig.pdf
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/dqb11d1vr7ts9tpkut7mi1s2sm/jukadudovudelagusotekoza.pdf
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/qfelrlm0mc0gtc31gr67kr9f18/48101817526.pdf
    • http://assushop.com/userfiles/assushop.com/file/83064829051.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=brompton+cystic+fibrosis+guidelines
    • 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_off0000d244.bin
0d5976b3e2fd3de1461ee942259728413ea5ae3608977339805fd7df26708492		 pdf-font-stream PDF embedded font (sfnt) at offset 0xD244 5556 bytes
font_01_sfnt_off0000e51b.bin
3ecd0236e2a2f98e4ce9d1c915d8b049f427dc71bf3feb0c89b5694d71cd120d		 pdf-font-stream PDF embedded font (sfnt) at offset 0xE51B 9852 bytes

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