Malicious PDF — malware analysis report

Static analysis result for SHA-256 e6872a9db16dee2d…

MALICIOUS

PDF

71.3 KB Created: 2021-09-19 15:51:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 81e5217443300b3ee635645cb6f7018a SHA-1: 2c0e53811bbb642abdb50490eefdfe7702ebf7f8 SHA-256: e6872a9db16dee2d337ba97fbd86ffeeb6ae583a59b0bd90acf56927b5d50361
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which are part of link farms hosted on compromised or disposable domains, suggesting a phishing or malware distribution scheme. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using such links to potentially redirect users to malicious content, and the 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' points to the use of compromised WordPress sites for hosting. The presence of embedded URLs and the overall structure strongly suggest an attempt to trick users into downloading further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://wastran.ru/uplcv?utm_term=download+vault+calculator
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ecef3b03df---50305905380.pdf
    • https://spacio.hk/attachment/file/68742564710.pdf
    • http://grandioso.asia/editor_upload_image/file/dibunakunonorodujo.pdf
    • http://qualityspices.in/ckuploads/files/rawizelibup.pdf
    • https://cafepiolho.com/uploads/assets/84228493264.pdf
    • https://cortopolis.ar/userfiles/file/fopexozewuvoxuv.pdf
    • http://semihkerpiccilervesupersound.com/upload/file/40710608736.pdf
    • https://unitedfightalliance.jordanadams.com/ckfinder/userfiles/files/viresovexukexav.pdf
    • https://bancodevida.com/bancodevida/admin/images/image/file/zijemiripu.pdf
    • http://cnokorea.com/userfiles/file/gexivibogasojafuwogod.pdf
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613d00e7bcbcf---77612693701.pdf
    • https://99shayari.in/userfiles/files/77749388906.pdf
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614173bbbfc40---7414049499.pdf
    • https://pointwebhost.com/calisma2/files/uploads/dozolopiriwel.pdf
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613f9141b2c26---zasabi.pdf
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/de566a57107ed8426f394a6c63e2aa5d/29883447973.pdf
    • http://physio-praxismitte.de/userfiles/84505783164.pdf
    • http://cabanagarden.hu/editor_up/39724367029.pdf
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/mbqkltlvgs41elujgthci6k3q4/wefanokuxodef.pdf
    • https://iaido-iaijutsu.ru/userfiles_exc/bobigef.pdf
    • https://urology-andrology.com/userfiles/file/32730556189.pdf
    • http://rvhifi.cz/files/file/mosuganovakosinoziruf.pdf
    • http://rockhouseschool.com/rockhouse/uploads/files/xefomajibabajutopaf.pdf
    • http://amsaneeraus.fi/userfiles/files/7314087356.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b74e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB74E 16792 bytes
font_01_sfnt_off0000cf65.bin
230ddb9bb7fc7ea5a735d38e002ce03d7a9135cc425d4ae969aa7e4a309fbce3
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF65 10224 bytes
font_02_sfnt_off0000e680.bin
a530d68f85d2c2210d30af1c3d54bba34b3a14b197bf75e65b8d07f5d62aaee4
pdf-font-stream PDF embedded font (sfnt) at offset 0xE680 15648 bytes