Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb18fa5f1499bac7…

MALICIOUS

PDF

82.4 KB Created: 2021-09-17 05:44:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 2dae1c245a7983ea0c89d59c8fdd889f SHA-1: 3bb99ce34906f367e750b22c6df6e3f99846d768 SHA-256: cb18fa5f1499bac71448725199ecf25927df410bc25c478ee69730f40b5df3b0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to compromised or disposable hosting, suggesting a link farm or phishing lure. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this, indicating the PDF is used to distribute or link to malicious content. No scripts were extracted, but the overall structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://123podkrovie.sk/editor_uploads/files/gakonudijepa.pdf In PDF document text
    • https://faceless.me/userfiles/files/vomajopizuninaduribi.pdfIn PDF document text
    • https://divinenine.net/userfiles/file/gosato.pdfIn PDF document text
    • https://namphuctourist.com/userfiles/file/fomiguwobidajazeliweboba.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/161384ddb8ac27---palajesazutipulevizun.pdfIn PDF document text
    • http://hstechno.com/userData/ebizro_board/file/tutuzubevafeti.pdfIn PDF document text
    • https://ce-mi.pl/uploads/userfiles/files/46735760123.pdfIn PDF document text
    • http://abwninemile.com/uploads/files/2097841438.pdfIn PDF document text
    • http://oldadmin.k12cart.com/media/files/8856556781.pdfIn PDF document text
    • http://studiofelician.com/userfiles/files/30661839473.pdfIn PDF document text
    • http://go-pxl.com/uploads/files/2982562679.pdfIn PDF document text
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/hu3dbbp5jsvik8rq7l9jjhko3m/38032306528.pdfIn PDF document text
    • http://baove24h.org/upload/files/19451249844.pdfIn PDF document text
    • http://yogo110.com/userfiles/file/42540167799.pdfIn PDF document text
    • http://holidayinntorino.com/userfiles/files/69849709832.pdfIn PDF document text
    • https://qnzar.com/files/mizineselarugusel.pdfIn PDF document text
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/97b546f18c23effa852f896e1be281e5/xobejizokotebawopero.pdfIn PDF document text
    • http://studiolauramoschini.it/userfiles/files/xebevikativi.pdfIn PDF document text
    • http://gestaocipa.com/public_html/Imagens/file/mufawapesovekunozalure.pdfIn PDF document text
    • https://cqc-material.com/app/webroot/userfiles/files/82218632172.pdfIn PDF document text
    • https://habibitours.net/ckfinder/userfiles/files/84596820853.pdfIn PDF document text
    • http://tz5168.com/uploadfile/image/2021/09/11/file/20210911_211200_116.pdfIn PDF document text
    • https://euforbiabulgaria.com/uploads/pages/files/lalifexujo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=mobile+usb+tethering+to+pcPDF 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_off0000dbab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBAB 10724 bytes
SHA-256: 40fc2dd6962d94dc6119a7f11f701b0277f5162ec9d97fc39f09edc75bfb5775
font_01_sfnt_off0000f40a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF40A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010c1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C1C 18448 bytes
SHA-256: 28938fdf087f42bfc25434b372c8cdc93644cacccb6564f01a8faff723da10b2