Malicious PDF — malware analysis report

Static analysis result for SHA-256 6138a8cd649f8b66…

MALICIOUS

PDF

84.3 KB Created: 2021-09-07 19:12:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 6bbdbf2f53d7e02c346fb81f14651bca SHA-1: 68e82a9e82c1e6cf9e0ab8880ee3f97caa7d75b5 SHA-256: 6138a8cd649f8b661e615aa9b4c28956034226bf7b8105244b13e781ed5530f5
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised websites or disposable hosting, indicative of a link farm designed to lead users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics and the overall structure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://zonwering-belgie.eu/ckfinder/userfiles/files/zisorijubunukafe.pdf In PDF document text
    • https://ceramicasvillaflor.cl/UserFiles/File/73037118072.pdfIn PDF document text
    • http://vaness-sens.fr/ckfinder/userfiles/files/11292957853.pdfIn PDF document text
    • http://nppgursaraijhansi.in/ckfinder/userfiles/files/83252655584.pdfIn PDF document text
    • https://suadienlanhhanoi.net/upload/files/pitegipewokifilefesikonap.pdfIn PDF document text
    • http://519pf.com/userfiles/files/fazebiwesapogusa.pdfIn PDF document text
    • http://challendor.com/fckeditor/upload/file/81650526790.pdfIn PDF document text
    • http://hockeydh.com/files/ups/files/nejosufasowoxa.pdfIn PDF document text
    • http://alt-1c.ru/userfiles/file/volopebunewuvukoris.pdfIn PDF document text
    • http://15449010.com/FileData/ckfinder/files/20210707_24ABA42AF6939458.pdfIn PDF document text
    • http://evevoyance.fr/adh/.-/file/pukedojawejisebite.pdfIn PDF document text
    • http://mcleod-bobbitt.com/clients/64742/File/rubaxopoxorarosopusozise.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/8mi2krmvvu14moa92hu8pn67j6/4383354890.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/5ab3666d023f62ce4753356295bf0268/notiroraw.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160bfbaaac196f---lizojesixunagedujapi.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/dssqrikifk4vansbpl9qjj4u03/18452847562.pdfIn PDF document text
    • https://www.aaptuk.org/ckfinder/userfiles/files/76925221048.pdfIn PDF document text
    • http://condosworld.com/abisol1/userfiles/files/21637864593.pdfIn PDF document text
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/50e0b97ac1132729da7bd4216095f3f2/92246450811.pdfIn PDF document text
    • http://shinex-auto.com/userfiles/file/42238236745.pdfIn PDF document text
    • http://malovanesklomh.cz/images/file/38411785606.pdfIn PDF document text
    • http://neuragen.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160940eee3a395---61077457025.pdfIn PDF document text
    • https://educhina.mn/editor/files/6410942571.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=oracle+primavera+tutorial+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_off0000e66f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE66F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE86 10700 bytes
SHA-256: 766ae5710d06396e23790456ac61f4921645a54dbcb29155a135af4338a515e7
font_02_sfnt_off00011722.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11722 17308 bytes
SHA-256: cc56c6df393017ab44c24f3c97c530eaa9ea23af2d497d6fb2e4dccb9d0303fa