Malicious PDF — malware analysis report

Static analysis result for SHA-256 387447ffeb856325…

MALICIOUS

PDF

116.1 KB Created: 2021-09-06 01:48:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7bb26a19289bb6473b83d5e71aa91d4c SHA-1: 76e688f00aa653fc360df8a9c2cfb69a961d44c9 SHA-256: 387447ffeb8563254cc6bfd83d2e02d0a409ee40955da921427c4b3e988a8369
172 Risk Score

Malware Insights

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

The sample is a malicious PDF, as indicated by ML classification and ClamAV detection. It contains embedded JavaScript and numerous links to external PDFs hosted on compromised websites, suggesting it's part of a phishing campaign. The 'SE_INVOICE_LURE' heuristic further supports the phishing pretext, aiming to trick users into downloading a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/885ae5e94868ebdf3650ca208a47cb40/65475987215.pdf
    • https://gamedunyasi.com/calisma2/files/uploads/1324060241.pdf
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3cfc60f30f---43422190662.pdf
    • https://comobrew.com/newsite/images/user_uploads/file/zefubu.pdf
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c9d1ae1f0b---33971808776.pdf
    • http://stoewebdesign.no/userfiles/file/wilakuzu.pdf
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084303520219---77654810032.pdf
    • http://bochosushi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a47801401f5---97787257509.pdf
    • http://mai-colle.jp/userfiles/file/78406598680.pdf
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b750bc6af4a---87354890663.pdf
    • https://nusamulticentralestari.com/Uploads/userfiles/files/81863277337.pdf
    • https://mariellatriolo.it/public/file/bejawukakatodoj.pdf
    • https://surupaceanu.ro/ckfinder/userfiles/files/15367609521.pdf
    • http://eros-arena.com/eros/userfiles/file/92773672079.pdf
    • http://e-kva.ru/admin/ckfinder/userfiles/files/pituvanas.pdf
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608404cba34fd---kavemasodozometar.pdf
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/160b6046bc3510---xufevukuvalesafazilif.pdf
    • http://gps-tw.com/CKEdit/upload/files/35493895712.pdf
    • http://gunjanjain.com/app/webroot/js/uploads/files/96880027918.pdf
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16093a107490a0---44703862308.pdf
    • https://tckontrola.hr/files/48308698612.pdf
    • http://alliance-ltd.com/userfiles/zebasibifozoxusilijuf.pdf
    • http://japhina.com/upload/file/dimipubatuxowo.pdf
    • https://gertiesbloomers.com/kousumi/nulook/upload/fckimages/file/53842255520.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=golpe+de+calor+pdf+2019
    • 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_off00015974.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15974 16792 bytes
font_01_sfnt_off00017186.bin
63243ab918d8478499b0d87bf969b2319ed6333545fd83fa9c46a02c201e8c65
pdf-font-stream PDF embedded font (sfnt) at offset 0x17186 22304 bytes
font_02_sfnt_off0001aa4e.bin
925b77eac125ac26ccb424496bd062eb6f164be8e4b7894a0c67269c98bb6970
pdf-font-stream PDF embedded font (sfnt) at offset 0x1AA4E 10652 bytes