Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8aaf1c6b7688e72…

MALICIOUS

PDF

75.0 KB Created: 2021-09-11 00:17:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-23
MD5: a624611c1a1831997f948bceaf3f3fec SHA-1: 540361cac4ffaf930162f82bf26fc216e181c876 SHA-256: c8aaf1c6b7688e727113ea4d18fc293419249327873ed872832c44c676d0c61d
162 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8621

Heuristics 6

  • 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
  • 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://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613b246a1e5e5---julijonaruromosadorur.pdf In PDF document text
    • http://bualuang101.com/backoffice/upload/files/pulirabizopujenagupig.pdfIn PDF document text
    • http://alphanaturehk.com/userfiles/file/64350900978.pdfIn PDF document text
    • http://ortosprendimai.lt/userfiles/file/rutejonojodesazom.pdfIn PDF document text
    • https://lekkermooi.nl/userfiles/file/favidipolizodij.pdfIn PDF document text
    • https://cristalensi.com/public/File/loxiwiwumamug.pdfIn PDF document text
    • http://pi-consulting.ch/download/9013343127.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/42734102716.pdfIn PDF document text
    • http://petraifevronii.ru/ckfinder/userfiles/files/pupogepuzowe.pdfIn PDF document text
    • https://varbackaforskola.se/ckfinder/userfiles/files/rajexineboxij.pdfIn PDF document text
    • https://underworldgear.com/upload/users/files/xeviv.pdfIn PDF document text
    • http://nhuaduongnhapkhauaz.info/upload/files/85957358571.pdfIn PDF document text
    • http://full814.com/upload/files/ronamesaxu.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bca650d631---jotewigofolupeteteja.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fed63f066e---90782369765.pdfIn PDF document text
    • http://decorstore.eu/upload/file/movufigewenazasosumozere.pdfIn PDF document text
    • https://tourpon.kr/FileData/ckfinder/files/20210902_A0EA7B00E6D8423A.pdfIn PDF document text
    • https://montpellier-business-plan.com/mbp/upload/images/images/upload/ckfinder/4176503346.pdfIn PDF document text
    • http://k-ookuma.com/js/upload/files/66717547466.pdfIn PDF document text
    • http://rothemtour.com/FileData/ckfinder/files/20210905_8F9F23B093522C49.pdfIn PDF document text
    • http://chi-kara.net/userfiles/file/doxexitigikutivizojaka.pdfIn PDF document text
    • https://ruedi-leuthold.com/userfiles/files/tiwavoranurupukekuzizuv.pdfIn PDF document text
    • http://klubbelgickychobrov.sk/editor_uploads/files/bajaxajenox.pdfIn PDF document text
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130bd75b2b64---76961269980.pdfIn PDF document text
    • https://daquin-ferriere.fr/userfiles/file/lepusawijowuzo.pdfIn PDF document text
    • https://nepalonlineexam.tisaracademy.com/userfiles/files/nufevotalet.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=parabola+general+form+to+standard+form+calculatorPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e624.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE624 19188 bytes
SHA-256: bde3677150bd77cae91a24270e5e233c7948c66a35e768751b93bd3d1ce267e7
font_01_sfnt_off000117c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1