Malicious PDF — malware analysis report

Static analysis result for SHA-256 110ff21088ae4ab7…

MALICIOUS

PDF

95.0 KB Created: 2021-08-22 02:29:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 6029f467755ebd43ae075e39bc87dc91 SHA-1: 740241ca65b2742bfcd62c247c734c339cd28a5f SHA-256: 110ff21088ae4ab77c7d9b635e99fc931fc182ffaa7ab5a1ed6caf1073b4ed6f
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicative of a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' confirms the nature of the document as a link farm designed to leverage search engine optimization.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://krisoc.ru/uplcv?utm_term=dieta+low+carb+menu+semanal+pdf PDF link annotation
    • http://earthtalismanjewelry.com/clients/b/b2/b27d4d76c51cd35ccef873a204118430/File/wamemixolubagedex.pdfIn PDF document text
    • http://chalappuram.com/userfiles/file/fomupapotazigegolada.pdfIn PDF document text
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/5c0e0d4364cd03bf69c1289c09adc08e/27654828140.pdfIn PDF document text
    • https://nasikampung.info/contents//files/xagavebasotovepe.pdfIn PDF document text
    • https://mamotato.ro/userfiles/file/xuniwefimoluvuf.pdfIn PDF document text
    • http://centromedicoveterinarioadda.com/userfiles/files/77023592743.pdfIn PDF document text
    • https://www.letspassdriving.co.uk/wp-content/plugins/super-forms/uploads/php/files/3ttqnsvth4vdrudqktdcove6kf/figowuvedidu.pdfIn PDF document text
    • http://meandnetworking.com/ckfinder/userfiles/files/savimudokijojobep.pdfIn PDF document text
    • http://thaiboxes.com/piceditor/file/watatenamu.pdfIn PDF document text
    • http://ducthoaudio.com/upload/files/dulani.pdfIn PDF document text
    • https://goodluckfishing.com/ckfinder/userfiles/files/pokapa.pdfIn PDF document text
    • http://nppgursaraijhansi.in/ckfinder/userfiles/files/73786175237.pdfIn PDF document text
    • http://provia-events.de/pics/fotos/1/file/kikojulejaxebuli.pdfIn PDF document text
    • http://henrycrawfordreunion.com/clients/1/19/1929e20d1ffebcad6d8b2a659e9c170d/File/96016890810.pdfIn PDF document text
    • http://beamstraffic.ae/amb/userfiles/file/sepiri.pdfIn PDF document text
    • http://tjsijiqing.com/ckfinder/userfiles/files/2021/0815/bc0dd732078743e7690bc992beceb7c1.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca92533079---telaxejupamej.pdfIn PDF document text
    • https://www.kasekimi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160843954b0ac0---tawupowapi.pdfIn PDF document text
    • https://artenika.pl/fck/file/35326450845.pdfIn PDF document text
    • https://flying-vikings.net/UserFiles/file/86869910870.pdfIn PDF document text
    • http://sujitonweb.com/userfiles/files/56814303836.pdfIn PDF document text
    • https://aspirans.com/files/file/40322324400.pdfIn PDF document text
    • 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_off00010ec6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EC6 17756 bytes
SHA-256: 9f808f1af394a99380639d8a5a2ba3a20908e48148957390f1c615d36c4e6cf6
font_01_sfnt_off00013bd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BD5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000153ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x153EC 11108 bytes
SHA-256: 394eb4f931b6793dcffcd30b1f6517d06965e7830044c6b13b0a6c152fd70fbf