Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec139cdc67420a2d…

MALICIOUS

PDF

86.3 KB Created: 2021-09-16 12:54:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 36637e93b8b9aa39803980991f4339e6 SHA-1: 0431b529f98911ec0e09412ea7c474413d38160f SHA-256: ec139cdc67420a2db92770ce30d021679a42803a20bacd77180f5791b09ffb9d
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to external sites, including those hosted on compromised WordPress installations. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware through these links. The document body is unreadable, but the heuristic firings clearly point to a link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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.
  • 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://officialbacknumber.org/editor_up/75484338518.pdf In PDF document text
    • http://studiodabo.eu/userfiles/files/maxinof.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/92381272641.pdfIn PDF document text
    • https://regiefranchet.fr/userfiles/files/89384470008.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/279cff791f4f1eda03db75e62d5e600d/salipus.pdfIn PDF document text
    • https://www.afoa.org.ar/backend/ckfinder/userfiles/files/sasabanepezomesufi.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613c228c58ab4---4124904470.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16137074c62e44---fopewezovawape.pdfIn PDF document text
    • http://nhuaduongnhapkhauaz.com/upload/files/pexikizakolizogapodaw.pdfIn PDF document text
    • https://beautifullifeuk.com/wp-content/plugins/super-forms/uploads/php/files/568fe9e5b6c65fae59ce7447d774876f/pemoxubekatajofegaju.pdfIn PDF document text
    • https://ewdel.cz/ckfinder/userfiles/files/73463280041.pdfIn PDF document text
    • http://stroykap.com/application/views/stroykap/userfiles/file/21303984063.pdfIn PDF document text
    • https://www.opdrrustukalac.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140a3c86e5c6---40188977520.pdfIn PDF document text
    • http://pwmtqatar.net/userfiles/file/tifozolavirinesujajovaw.pdfIn PDF document text
    • https://chineseclothingonline.com/File/tutenudubowuvugajotadebor.pdfIn PDF document text
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/pdmd1b0stbr2k6bdhqig4uragn/86864437339.pdfIn PDF document text
    • http://npi-management.com/ressource/site-image/files/24545808760.pdfIn PDF document text
    • https://ikitellirezistans.com/upload/files/17178148789.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612edf8c04c16---45987115000.pdfIn PDF document text
    • http://oasis-inwaste.asia/files/file/7427768420.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16134fdb4dd77d---24246150126.pdfIn PDF document text
    • http://utcsp.rustyramone.com/uploads/files/rabatawukibijatipu.pdfIn PDF document text
    • https://cairparavel.ro/app/webroot/files/userfiles/files/fawelibazugiketuduko.pdfIn PDF document text
    • http://mobilahomedesign.com/userfiles/files/dufibejuv.pdfIn PDF document text
    • http://agro-norwa.pl/userfiles/file/80831531653.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=ematic+agt419+user+manualPDF 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://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/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_off0000ebc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBC9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000103db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103DB 17948 bytes
SHA-256: 2980b5bf98111d2be179ca267c32fb9faba4971da3c9901a7f6fa8b180f6a33a
font_02_sfnt_off000132a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132A1 10836 bytes
SHA-256: de9b5055f2dd1cda3f76ec3f1cb0ed3d3204a16ac86b83986077dc35088810ca