Malicious PDF — malware analysis report

Static analysis result for SHA-256 39d9166e31f20953…

MALICIOUS

PDF

69.3 KB Created: 2021-09-17 01:15:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 565ef3a9ca4740ac778eb8db501715c7 SHA-1: 5a2a48940e14aab3c3b27a58a93b26703d605334 SHA-256: 39d9166e31f2095321fb91a3a22b48bea7409d7b82d75f0241274eab21713bd5
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to compromised WordPress uploads or disposable domains. This suggests the document is designed to act as a link farm, potentially for SEO manipulation or to redirect users to malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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.
  • 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://alt-1c.ru/userfiles/file/12460695565.pdf In PDF document text
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/c53e2ff27c9d3e08aa4d09392de540f3/23687678191.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/161430c6f4e963---sinediruletix.pdfIn PDF document text
    • http://enjoy.sk/editor_uploads/system/files/50434015890.pdfIn PDF document text
    • http://genbreedpublisher.com/files/upfiles/file/limusuxesomu.pdfIn PDF document text
    • http://wonderful-foods.net/userfiles/file/83958260747.pdfIn PDF document text
    • http://aristosaigonhotel.com/uploads/files/40284752223.pdfIn PDF document text
    • http://digivideos.net/ckfinder/userfiles/files/ninakazabikotudidelojug.pdfIn PDF document text
    • http://assisdrive.pt/userfiles/file/39893735879.pdfIn PDF document text
    • https://www.barefoothoa.com/webroot/js/ckfinder/userfiles/files/25603532048.pdfIn PDF document text
    • https://hw-power.com/uploads/ckfiles/files/614040818f91e.pdfIn PDF document text
    • https://rivieresoceanie.com/ckfinder/userfiles/files/72322498017.pdfIn PDF document text
    • http://globalbando.com/DATA/upload/files/202109170103151498.pdfIn PDF document text
    • http://epwuae.com/userfiles/file/bedojexo.pdfIn PDF document text
    • http://zanethompson.com/userfiles/file/20827379413.pdfIn PDF document text
    • http://bandbaajabarat.com/ci/userfiles/files/pefog.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/161353e719cced---rexipapedofulazebinir.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/16137ec190d704---37152940719.pdfIn PDF document text
    • https://ixiu-23.com/uploads/files/202109152251426218.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/n8s924qri6mqbsuvfd16sm2d45/68057210697.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=stephen+hawking+accomplishments+listPDF 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://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_off0000b1b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1B0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c9c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9C7 10976 bytes
SHA-256: ab9e3ae38f08f1dc27e2f68ea68b1ca47db90309c691fbc8b8d1c7b60c803237
font_02_sfnt_off0000e31c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE31C 16596 bytes
SHA-256: f39885bda7184b730abb72fb1017f140a16963835f251a869521785d13b3d382