Malicious PDF — malware analysis report

Static analysis result for SHA-256 6e135e267c68a8c1…

MALICIOUS

PDF

85.9 KB Created: 2021-09-15 12:57:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 4887333b77a768d5015dbcc6ee6b5ea5 SHA-1: 66c7dcf4e04ea7172cba9023c8214414caa2a269 SHA-256: 6e135e267c68a8c130b7ac2b07e18fcfe3873cbb459ccc260437b4b0ede2d186
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on potentially compromised CMS platforms. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking readable content but containing embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://riversedgefm.com/files/file/minudadoputinidel.pdf In PDF document text
    • http://tetraeng.it/userfiles/files/vexozabavubesepuresij.pdfIn PDF document text
    • http://finara-v.com/file_media/file_image/file/zakikerivaxoxosel.pdfIn PDF document text
    • http://africareview.in/userfiles/file/1956485339.pdfIn PDF document text
    • http://automotiveenergy.cz/userfiles/file/vudabope.pdfIn PDF document text
    • https://www.leasing.net.in/ckfinder/userfiles/files/vukagugaboged.pdfIn PDF document text
    • http://thienminhgroup.com/uploads/userfiles/file/todojuwuma.pdfIn PDF document text
    • https://zlato-invest.cz/upload/files/sojizox.pdfIn PDF document text
    • http://animalscipublisher.com/files/upfiles/file/rojadodiresegutelegek.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613b290c76761---84949311439.pdfIn PDF document text
    • http://urgentcarepb.net/userfiles/file/kipajabipoxunuxodenobufo.pdfIn PDF document text
    • https://melz-feu.ru/upload/sisis.pdfIn PDF document text
    • http://svatba-emi.com/uploads/pages/files/90717401598.pdfIn PDF document text
    • https://grandegroup.net/files/55641179159.pdfIn PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/161305f6e9aaf6---96751077842.pdfIn PDF document text
    • http://etcpremium.com/userfiles/files/22688020960.pdfIn PDF document text
    • http://worldtile.net/jangheung/userfiles/file/wisizokefiv.pdfIn PDF document text
    • https://rtvpuls.com/ckfinder/userfiles/files/66823362171.pdfIn PDF document text
    • https://europartner2.pl/uploads/losojo.pdfIn PDF document text
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/5ec8f2b682744f84aed849705fcdeed1/88558195997.pdfIn PDF document text
    • http://montpellier-business-plan.eu/mbp/upload/images/images/upload/ckfinder/72282150396.pdfIn PDF document text
    • http://www.vlaamspatientenplatform.be/_plugin/ckfinder/userfiles/files/25365635118.pdfIn PDF document text
    • http://veewood.com/file_media/file_image/file/pajavusarutokafozuta.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=saytzeff+rule+example+with+mechanismPDF 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_off0000e979.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE979 17960 bytes
SHA-256: caae295e1a6b5d8001187d9fe2b8c2fa51d06b9cb1597a6e0bfa5f782584e64f
font_01_sfnt_off00011826.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11826 11160 bytes
SHA-256: 1d9bac15691d244e1b30cba21e1587d9c9a262d9d149fb9be631facb970087c6
font_02_sfnt_off0001322d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1322D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1