Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8c06c8ce40ad3c4…

MALICIOUS

PDF

71.1 KB Created: 2021-09-10 00:27:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: bbc1187021fea4648e41cd8480da2492 SHA-1: dde5508ea42897517b42d0674ed8311ba0af4e27 SHA-256: a8c06c8ce40ad3c44751bb588536ce5964453fce5be646bf0d501d34f2824576
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which are identified as part of a link farm. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution through SEO poisoning. The PDF structure itself is also flagged for suspicious object definitions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://valkexclusief.reviewz.eu/app/webroot/files/userfiles/files/81073819741.pdf In PDF document text
    • https://profipreklady.cz/www/ckfinder/userfiles/files/doniluvuxuroloziluw.pdfIn PDF document text
    • https://foundlight.ca/home/foun6192/public_html/files/custom_files/file/rafifid.pdfIn PDF document text
    • http://roseeskin.com/userfiles/file/20210906185048.pdfIn PDF document text
    • https://taperagi.com/contents/files/remuxifokek.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613a7b6ed8ef0---84898678415.pdfIn PDF document text
    • http://ruihuitax.com/files/file/najosufokedidugeragok.pdfIn PDF document text
    • https://jlgardner.org/home/jlg/public_html/ckfinder/userfiles/files/fonilenoduzemul.pdfIn PDF document text
    • https://efsanepin.com/calisma2/files/uploads/ferukives.pdfIn PDF document text
    • http://geofer.eu/userfiles/files/zatadamijesinonareru.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/38382787954.pdfIn PDF document text
    • https://alsultantrading.ae/userfiles/files/35565220978.pdfIn PDF document text
    • http://thinhhoanggia.vn/Images_upload/files/noropowu.pdfIn PDF document text
    • http://mayingiabao.com/upload/files/39790786377.pdfIn PDF document text
    • https://takitech.hu/userfiles/file/44558593446.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131f435cd7e5---90493430560.pdfIn PDF document text
    • http://myucpb.com/userfiles/file/kokupufasa.pdfIn PDF document text
    • http://nscenter.cn/upload/files/lozazotegesek.pdfIn PDF document text
    • https://masihpt1.com/contents/files/jesesukavaritagu.pdfIn PDF document text
    • http://theofficefurniturestore.com/ckfinder/userfiles/files/miwuxigezikuluderovut.pdfIn PDF document text
    • http://ajtoablakcentrum.com/_user/file/11144015360.pdfIn PDF document text
    • http://usmleworkout.com/files/file/tasofakekemanexuzuditiza.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=lehninger+pdf+downloadPDF 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_off0000b553.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB553 16100 bytes
SHA-256: 8c531dfc702c2ad9067759e4a5acfe019bffd73824070203b9d134827395ce9d
font_01_sfnt_off0000dee4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEE4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f6fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6FB 10556 bytes
SHA-256: e6c2040d2cfaf7707bf53bfdf719873247a5c765152d2ca2adeb1d1940c264cc

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