Malicious PDF — malware analysis report

Static analysis result for SHA-256 6894f0afd4e6ffa9…

MALICIOUS

PDF

75.7 KB Created: 2021-09-18 13:14:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b89252cf42c5e3f765a8230c72c8eb7b SHA-1: d98fddb76ffb977c6dbd003b3245cbcdc8a3ec27 SHA-256: 6894f0afd4e6ffa975823f06b58978e235d596c94abcbae13a4d6b03b3fa4a99
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to other PDFs hosted on compromised websites or disposable domains, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the structure and URL analysis point to a multi-stage attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://sensesgrouphk.com/louis/STARKGROUP/ckfinder/userfiles/files/15155989283.pdf In PDF document text
    • http://www.thaiboat.net/image/upload/File/gonojemirisedu.pdfIn PDF document text
    • http://ei-windykacja.pl/upload/file/45812870958.pdfIn PDF document text
    • http://kino-cosmik.ru/sadm_files/bixesijijofogaxovukepeke.pdfIn PDF document text
    • http://montagnobozzone.it/userfiles/files/46587244423.pdfIn PDF document text
    • http://girc.ncue.edu.tw/ckfinder/ckfiles/files/38665924160.pdfIn PDF document text
    • http://exito-opakowania.pl/userfiles/file/xesurugal.pdfIn PDF document text
    • http://www.synagoge-stommeln.de/ckfinder/userfiles/files/wafotuzovo.pdfIn PDF document text
    • http://baugeraeteverleih.de/benutzerdateien/76721704588.pdfIn PDF document text
    • http://100gastro.cz/soubory/files/pidadurivilajofu.pdfIn PDF document text
    • https://yourwebcenter.com/files/file/13034628029.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161408bed831eb---nuxepa.pdfIn PDF document text
    • http://studiolaviano.it/userfiles/files/renawasilez.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1612f698609e35---44121508768.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/161374037c354e---66707124747.pdfIn PDF document text
    • http://sergeisurzhin.ru/ckfinder/userfiles/files/gumumano.pdfIn PDF document text
    • http://innersolutions-uk.com/file/dosogeravabuwojopenonin.pdfIn PDF document text
    • http://bkmarine.net/ckfinder/userfiles/files/1630540697.pdfIn PDF document text
    • http://meyergarden.com/ckfinder/userfiles/files/xagazedefoja.pdfIn PDF document text
    • http://gioiacompany.net/images/upload/file/fefifiponafutegir.pdfIn PDF document text
    • http://npcbalkan.net/ckeditor/ckfinder/userfiles/files/siveladevuzobo.pdfIn PDF document text
    • http://przychodnia-felinskiego.pl/uploads/editor/file/14061501130.pdfIn PDF document text
    • http://gyuco.com/uploadfile/files/20210916_202144.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=ld+player+latest+version+for+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_off0000c5a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5A9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ddbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDBB 16288 bytes
SHA-256: e7490c7b8b5dec06d7ad81e90db443659672f7a2c8cfdb8d199f37f0819d41fc
font_02_sfnt_off000107d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107D2 10752 bytes
SHA-256: 2d8c3a2bf74da31bb7d9b10fe208497692d65b99ca4aa0b5c320c0cad946da01