Malicious PDF — malware analysis report

Static analysis result for SHA-256 c78bc199dfa91630…

MALICIOUS

PDF

85.8 KB Created: 2021-09-14 08:10:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: c07d8f80f8906023a4db5cf9c93f2a5c SHA-1: abb27ba159a47d3bd3a8389adf0286b02bbdc169 SHA-256: c78bc199dfa9163052b16604cf229068e9c35e5d547c5cbf1c69d85131e66e70
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier, indicating malicious intent. It contains numerous embedded URLs, many pointing to compromised CMS upload storage or disposable hosting, suggesting it's designed to redirect users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true purpose but reinforcing the link farm nature.

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://garglob.ru/uplcv?utm_term=iphone+6s+plus+in+bangladesh+price PDF link annotation
    • http://thriftstorewebsites.com/flash/thriftstorewebsites.com/file/19177021237.pdfIn PDF document text
    • http://hyunsin.net/userfiles/file/31990940235.pdfIn PDF document text
    • https://almuhja.net/ckfinder/userfiles/files/kasusigematol.pdfIn PDF document text
    • https://embassyinvietnam.com/webroot/img/files/pogiwebanazesaw.pdfIn PDF document text
    • http://bright-inter.com/file_media/file_image/file/32313004655.pdfIn PDF document text
    • http://186086.com/upload/files/39881801386.pdfIn PDF document text
    • https://korankertas.com/contents/files/pujafike.pdfIn PDF document text
    • http://altadirezione-consulting.it/userfiles/files/88208657891.pdfIn PDF document text
    • http://xsjsbzrw.com/uploads/files/30659781609.pdfIn PDF document text
    • https://stpatswatertown.org/ckfinder/userfiles/files/60834443996.pdfIn PDF document text
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/9df8a3b285e9cc0a81d882575ac96248/69722967261.pdfIn PDF document text
    • http://desushibar.com/userfiles/file/vudatufarevakosugevumama.pdfIn PDF document text
    • http://budgettranslation.hu/sites/default/files/file/74451575384.pdfIn PDF document text
    • http://egyptlance.com/userfiles/file/logibuda.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613771d660c64---12529053674.pdfIn PDF document text
    • https://cristalparkhotel.com.ve/ckfinder/userfiles/files/ritezifikuluredugosowe.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b947999bed---17188155210.pdfIn PDF document text
    • https://sklepbonus.pl/userfiles/file/jukaxogixuxodulot.pdfIn PDF document text
    • http://supermarketdv.ru/files/file/nemut.pdfIn PDF document text
    • http://fskyok.com/uploadfile/files/34289656056.pdfIn PDF document text
    • http://pttaccounting.com/userfiles/files/48035326115.pdfIn PDF document text
    • https://buyafranchise.org/files/files/tinadumaxatukozibubuti.pdfIn PDF document text
    • https://hoangvan.vn/wp-content/uploads/files/zotigawetegawiwavetowek.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_off0000e27e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE27E 11052 bytes
SHA-256: 2c54d093d0477ced99d7d1e26c2f512c30dec6800df0839038f770be2953b21f
font_01_sfnt_off0000fbb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBB3 20420 bytes
SHA-256: 578a5b242bca1f4ebe4109d72a73ebfbfbb20811a951a0ff2efe4ed0e4df5a4a
font_02_sfnt_off0001310b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1310B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1