Malicious PDF — malware analysis report

Static analysis result for SHA-256 9156cf7d5fd27b3f…

MALICIOUS

PDF

74.3 KB Created: 2021-09-19 14:21:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 64f85dde9b5474a2dce97ccf66eb984c SHA-1: 14849615212986f7ba851e956e5fc1645236c73d SHA-256: 9156cf7d5fd27b3f8a6791b40f36e3d0506b807b48e736a1c15b041592d96c6e
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The embedded URLs, while numerous, do not provide a clear second-stage payload, but the overall structure points to an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/8fd6a3d87339f3219e6dc360e0b76585/78015074283.pdf
    • https://goodluckfishing.com/ckfinder/userfiles/files/benovovi.pdf
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1612fb14156824---linav.pdf
    • http://www.lircai.com/web/inline/file/gipawokepogixuxe.pdf
    • http://yonseri.org/userfiles/files/32196319897.pdf
    • http://brucemayrockinstitute.com/assets/ckfinder/core/connector/php/uploads/files/mupavufilu.pdf
    • http://flyingfish-stay.com/userfiles/file/46479469547.pdf
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/bca660spetkp9564bpqsjn3kt4/45674605922.pdf
    • https://faktxeber.com/resimler/files/39883114815.pdf
    • https://nieruchomoscikomercyjne.co/files/file/vegabexivusedotaw.pdf
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/16143602999c9f---muzokexizevegav.pdf
    • https://aksusu.com/upload/files/56989038655.pdf
    • http://wksystems.net/HotelEstimator/userfiles/file/piwovoporuwabazi.pdf
    • http://smepil.com/ckeditor/userfiles/files/savuzopidi.pdf
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1612ec5ed47274---64748616565.pdf
    • https://www.confirmedtour.com/files/66851937996.pdf
    • http://hycxchina.com/filespath/files/20210917034906.pdf
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/68433f5fbd7464c05954a97fae6dece0/xivazibigedozivejika.pdf
    • https://cristalparkhotel.com.ve/ckfinder/userfiles/files/xobetebatolize.pdf
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/s037nclet30905tee5qnfuig87/berajusodip.pdf
    • http://superfasttv.com/uploads/files/fafifedotexosofejiresupa.pdf
    • http://fujiya-la.com/uploads/files/pejanomupav.pdf
    • https://music-group-store.com/upload/files/53444267925.pdf
    • http://tubesealer.com/uploaded/file/5635193786137f052a6658.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=doctor+battery+apk
    • 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_off0000b8a4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB8A4 16792 bytes
font_01_sfnt_off0000d0b6.bin
4b0e883572ed2404ebcf0820e409589acd6a5a7496ec98d53deb31fa0b8759d3
pdf-font-stream PDF embedded font (sfnt) at offset 0xD0B6 20532 bytes
font_02_sfnt_off00010464.bin
4dc7091518ae43391e507f11fcbead7b94d5343203c3f5a3fc03de7b839e4cd3
pdf-font-stream PDF embedded font (sfnt) at offset 0x10464 10304 bytes