Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca4bf739c61346d5…

MALICIOUS

PDF

58.7 KB Created: 2021-09-13 07:20:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: aa8f9949a1abbb506e74cdac30ed17ca SHA-1: 625213a7f8d0ef56237f06d5c956fb7bc5a7f2af SHA-256: ca4bf739c61346d5b7e16930b7d71c7712b48e9c88864b78c5f23517e9afa0a8
154 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated maliciousness. Heuristics identified it as a link farm with many external URIs, some pointing to compromised CMS uploads or disposable hosting. The document body is unreadable binary data, suggesting it's not intended for direct user interaction but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6932

Heuristics 5

  • 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.
  • 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 https://huntic.ru/uplcv?utm_term=ceh+v11+lab+manual+pdf PDF link annotation
    • http://bioident.pl/photos_fck/file/mokup.pdfIn PDF document text
    • http://grappin-annat-como.com/userfiles/grappin-annat-como.com/file/lawamelofuso.pdfIn PDF document text
    • http://kibbkw.com/uploads/files/niwatijesod.pdfIn PDF document text
    • https://icon-studios.com/userfiles/file/xagijaluwisowokimukenezej.pdfIn PDF document text
    • https://tims.ro/ckfinder/userfiles/files/dememolubuzelo.pdfIn PDF document text
    • https://ostrichpharmaceuticals.com/userfiles/file/2807632651.pdfIn PDF document text
    • https://sieuviet.net/webroot/img/files/31331111814.pdfIn PDF document text
    • http://coverybox.box8websites.com/ckfinder/userfiles/files/38586717098.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac6f479fdf---674591879.pdfIn PDF document text
    • https://euforbiabulgaria.com/uploads/pages/files/kaguwigemuvowezutud.pdfIn PDF document text
    • http://munsusa.org/userfiles/file/20210912054936.pdfIn PDF document text
    • http://cp-1.ru/userfiles/files/52391292987.pdfIn PDF document text
    • http://king-tableware.com/uploads/files/202109130254548258.pdfIn PDF document text
    • http://jayeonrak.com/upfile_editor/2021/files/13054802656.pdfIn PDF document text
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/04d569ae5beb54f788cddfb4b12f0eec/fokugemigalegojuvewikag.pdfIn PDF document text
    • http://chatyzvule.cz/uploads/82082578831.pdfIn PDF document text
    • http://orderkiwicafe.com/uploads/files/tutusogidejusesojog.pdfIn PDF document text
    • http://goddesshair.net/upload/users/files/wizijavurura.pdfIn PDF document text
    • http://xinxinhouseware.com/uploadfile/files/4580199788.pdfIn PDF document text
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/d3cdfb86a91e66d5d07c8b000bf76e19/josixodifelijemidoxet.pdfIn PDF document text
    • http://blueleaves.ru/userfiles/file/zigap.pdfIn PDF document text
    • http://www.oteliapelsin.ru/ckfinder/userfiles/files/18946763779.pdfIn PDF document text
    • https://groupburuemas2.com/contents/files/degofugo.pdfIn PDF document text
    • http://modra-skola.cz/userfiles/file/falalulipojumajadizeginev.pdfIn PDF document text
    • http://2sisaccount.com/userfiles/files/76478226543.pdfIn PDF document text
    • http://ytovietnam.net/ckfinder/userfiles/files/40713426873.pdfIn PDF document text
    • https://betenagro.com/sites/default/files/file/jewidatir.pdfIn PDF document text
    • http://crossfit28.com.s125853.gridserver.com/siteuploads/editorimg/file/kizojarigilorivizefokim.pdfIn PDF document text
    • 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_off0000b359.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB359 14460 bytes
SHA-256: 767c1ac6f06e4d3e7d70786329c843c2031216ee907aacb9be8592d66abf697b
font_01_sfnt_off0000d793.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD793 10576 bytes
SHA-256: 53c09e93ecab21586cf4b9efbbdc4c0f4382c9c62a0127c3f34ef0c682de0f76