Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4b159585b9f33b7…

MALICIOUS

PDF

73.4 KB Created: 2021-09-06 09:19:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 8c64d451b2a39bcd791aaf9dce6e04c7 SHA-1: 6700b51a10bb20c843d38d88df9cd3c192fa2b92 SHA-256: d4b159585b9f33b7e8e5f6ea096226243fda8219fa5a22444f82ae1cdd46af40
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, flagging it as a phishing trojan. It functions as a link farm, containing numerous URLs that point to external resources, including some hosted on compromised WordPress upload directories. The primary purpose appears to be directing users to potentially malicious content through a series of indirect links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • 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
  • 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://birotex.rs/images/files/vazuzopinafurobexogufi.pdf In PDF document text
    • http://bycongroup.com/UserFiles/file/josizisep.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d41179e1654---11805634427.pdfIn PDF document text
    • http://suachuaspa.com/upload/images-content/files/verazurivimovamo.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/f6f71a2749acd7ea79de7c6685c7c3e1/momokisiveb.pdfIn PDF document text
    • https://pharma-tools.pl/galeria/file/wudirosatugukig.pdfIn PDF document text
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/9590c4c4a5f84cd7d6a356dc56e8cf6b/89296961172.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/v63511eln1ue7k17k0vsb3f6gi/62829511892.pdfIn PDF document text
    • https://adlinefor.com/home/webagen/public_html/korn/data/file/mijatuletoluros.pdfIn PDF document text
    • https://martabaktelor.com/contents//files/73407932646.pdfIn PDF document text
    • https://www.basur-tedavisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160700bdd35f57---kigakidojejilidafigas.pdfIn PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/1a276bea1306ff728e56725925e45462/73208000920.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/16079deec98a3c---69000155083.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/16087a6af61f4e---42385705364.pdfIn PDF document text
    • https://realestateconnect.biz/wp-content/plugins/super-forms/uploads/php/files/qhteok6s42r5c8n3q9spm835f2/7721574005.pdfIn PDF document text
    • http://sammyuriasproperties.com/userfiles/files/bobanaxipa.pdfIn PDF document text
    • http://www.css-jp.com/upfile/files/2021/06/28/8221276177.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160805a5e1ce8d---4980950625.pdfIn PDF document text
    • http://commandhousecreations.com/uploads/files/62844681388.pdfIn PDF document text
    • http://beijingxinzhi.com/userfiles/file/20210516164411_2106554630.pdfIn PDF document text
    • http://dentherapia.hu/files/file/72899073517.pdfIn PDF document text
    • http://anandtouristcorporation.com/uploads/sizevubikenurigi.pdfIn PDF document text
    • http://arunimaflavours.com/userfiles/file/favapigexirefelaramozo.pdfIn PDF document text
    • http://konditsionery-reutov.ru/upload_picture/file/wijomefe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=architectural+acoustics+book+pdfPDF 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_off0000bcfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCFB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d50d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD50D 16292 bytes
SHA-256: 8dcb280cd93993b8765ac1b7fa766132366fbc792e0dfe9e52b22051cfc0d531
font_02_sfnt_off0000fe80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE80 10924 bytes
SHA-256: 7038b7a99eb96601c2baf4faa13bdc222afda2460f95b54d724443de8c4a18bc