Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8a55ab22e47a533…

MALICIOUS

PDF

81.6 KB Created: 2021-09-18 20:06:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 18207f6c2f564c58c1e4803012a84d35 SHA-1: aa3d3371472b8f35dff55b252a7a785788e4ad2b SHA-256: a8a55ab22e47a5330ef5ea21a239f69bdff31f9c12deaae33e2b6149ea95a635
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing a link farm pointing to various PDF files hosted on potentially compromised websites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were directly extracted, the PDF structure and embedded URLs suggest an attempt to redirect users to malicious content, possibly exploiting PDF vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://cooperadora.grupocreartel.com/documentos/archivos/66099314879.pdf
    • http://massvt.sk/editor_uploads/system/files/fexosepo.pdf
    • http://vitanova-cattery.com/upload/file/disefivuvudolujinavizaj.pdf
    • https://horgaszvelem.elelmiszer-hazhozszallitas.hu/ckfinder/userfiles/files/puzimoboxodofeje.pdf
    • http://phoiinnhiet.com/images/uploads/files/65641906333.pdf
    • http://karate-talence.com/newsite/userfiles/files/larikokipisedesopafonazu.pdf
    • http://thementalhealthadvocates.org/files/userfiles/file/50889475395.pdf
    • http://cbgnfinance.com/userfiles/file/xosixezuxu.pdf
    • https://charteriraq.ir/basefile/charteriraqir/files/salimafefipewe.pdf
    • https://g4m3s-4p1-12s1.com/contents/files/66459166400.pdf
    • http://sumosushingrill.com/uploads/files/83842853401.pdf
    • http://danguykhoidoanhnghiephp.vn/Upload/files/wesipegewexijesivese.pdf
    • https://ketdoanbus.com/webroot/img/files/koros.pdf
    • http://onnetsolution.in/userfiles/file/62377884525.pdf
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/1585df4d3952b72a808d9aea1ff63a86/1967914091.pdf
    • http://abwcockeysville.com/uploads/files/numavapipetugibugotez.pdf
    • http://obchodsezlatem.cz/upload/files/mulepafoxiduzonenukupoja.pdf
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/161405f0f41d9d---10851641479.pdf
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613ec5c26e6e0---30920374060.pdf
    • http://goldenbaycruisesagent.com/userfiles/file/99547237799.pdf
    • https://nulifeus.com/~nulife/userfiles/file/34115157817.pdf
    • http://americansemitruckparts.com/d/files/paguwumimaxul.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=lego+jurassic+world+apk+obb
    • 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_off0000d8c3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD8C3 16792 bytes
font_01_sfnt_off0000f0d5.bin
c71861566b5b4fa8bea513b95fbc597e2ad4f5a210bab938075e9e66904ebb9d
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0D5 17932 bytes
font_02_sfnt_off00011f83.bin
fc47e6a1424e9a8e5ef73df00b1e13f92faa0a654c1b04953b48e8b591e053f7
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F83 10992 bytes