Malicious PDF — malware analysis report

Static analysis result for SHA-256 c9926b9dcc538bc7…

MALICIOUS

PDF

95.5 KB Created: 2021-07-23 13:18:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 48749e4bfcec60d7bd6ed04d6a28e86f SHA-1: 7d226e1572a67ceaa9f423c2aec7fdf555ea0486 SHA-256: c9926b9dcc538bc7fc56101811b28cc54c011e190236de4aae4bbce8d2d326ba
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites and other disposable hosting, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. The file's structure and numerous external URIs are consistent with a malicious PDF designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/v6lkfeje59k9fdjfo9sqs4ddn9/67571397880.pdf
    • https://ilcaminodaugo.it/file/moxamiromisizokedunulijes.pdf
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e4f6bdb557---kisaxotojeropitaneb.pdf
    • http://altiro.nl/home/tjerk/file/30495605875.pdf
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/ae8936ad542be1c46c7e52fee0382b30/fumepogot.pdf
    • http://ototavandosemesi.com/resimler/file/nazaxiju.pdf
    • https://btsis.com/upload/ckfinder/files/58301285600.pdf
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cdbf9ec9c57---kusirelofamilazarufupolo.pdf
    • http://zabradli-znerezu.cz/userfiles/file/foxunakulujop.pdf
    • http://mariangelesorrico.com/galeria/files/15500946461.pdf
    • https://autotrans911.com/thread/admin/uploads/file/99668412979.pdf
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/160963d95e4730---78209553787.pdf
    • https://hunde-katzen.at/soubory/38670957867.pdf
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/765uediuepj5jnv4u4rdbirhed/bebavuvo.pdf
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16071a144269b8---87935575505.pdf
    • https://hanahana.vn/media/ftp/file/4001761714.pdf
    • http://romanakladatelstvi.cz/userfiles/file/xoregamugidibo.pdf
    • https://www.kunapak.com/wp-content/plugins/super-forms/uploads/php/files/jic5fphnpql430n3rlss5va205/dasazexokij.pdf
    • https://afra24.com/basefile/afra24/files/bujatidanavukavuko.pdf
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160af57b9a9fa7---40992492396.pdf
    • https://nhaccugiare24h.com/uploads/userfiles/file/vubuzetexakavizikalok.pdf
    • http://vipnjl.com/userfiles/files/tiladozanomakamerarofuk.pdf
    • http://andlupa.com/userfiles/file/zumemamud.pdf
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16073446216d6c---vowenakofoximobog.pdf
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16081262bba089---telid.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=surreptitious+in+sentence
    • 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_off00011047.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11047 16792 bytes
font_01_sfnt_off00012859.bin
488a3b076457b84211d3c67390e3d78897add2586207a5eacb09ad60579ffb93
pdf-font-stream PDF embedded font (sfnt) at offset 0x12859 18092 bytes
font_02_sfnt_off00015833.bin
7af61644197cd26796a8681c33b99206f33dff6591eeb1eb482a9988b3153f25
pdf-font-stream PDF embedded font (sfnt) at offset 0x15833 10332 bytes