Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5535da3381b5b60…

MALICIOUS

PDF

71.6 KB Created: 2021-09-25 15:34:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c215b1fc921b261ac414f425b7375e91 SHA-1: 710e50c97c67c638f53a733e5da7455be8a78cc3 SHA-256: c5535da3381b5b601b78ad8bf562dca132e75e28ef595a7ff256c8bf32fc9335
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised WordPress upload storage, suggesting it's designed to host malicious files or redirect users to phishing pages. The presence of multiple unknown URLs further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9885

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://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ef18c0bd72---2286795440.pdf
    • https://flardochform.se/userfiles/file/59888477392.pdf
    • http://shijijiaming.cn/filespath/files/20210913211233.pdf
    • http://www.como-grup.ro/fisiere/file/14539286883.pdf
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613912cbc6619---83856144212.pdf
    • https://ratoempat.com/contents/files/pizibiwasonejikiga.pdf
    • https://ketex.com/trcgp/ckfinder/userfiles/files/zovep.pdf
    • http://www.mamafoundation.cz/ckfinder/userfiles/files/goromisizagoxidatazatu.pdf
    • http://yuhuimachinery.com/d/files/70017470240.pdf
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/1614682cf40749---barukurazaxapaxovuletu.pdf
    • https://muratay.nl/userfiles/file/monuxepixel.pdf
    • http://malbreil.com/userfiles/file/rimebiwewer.pdf
    • http://labsshop.com/d/files/8752024380.pdf
    • https://calendarsunrooms.com/userfiles/files/8627380528.pdf
    • https://blagoustroystvo24.ru/ckfinder/userfiles/files/35063559138.pdf
    • http://kingsfci.com/userfiles/file/duduberofa.pdf
    • http://sgrappresentanze.eu/userfiles/files/fapopevaj.pdf
    • https://cooperadora.grupocreartel.com/documentos/archivos/36888782376.pdf
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613728ebeba69---milumuterivulat.pdf
    • http://namngonviet.com/user-/files/biwow.pdf
    • http://sqc.jp/user_data/editor/ckfinder/core/connector/php/upload/files/16349862593.pdf
    • http://phunggia.biz/userfiles/file/lawabutojise.pdf
    • http://spy-military-labs.com/userfiles/file/28831540817.pdf
    • http://dancephoto.ru/userfiles/files/tuvidobavijetikunaxosog.pdf
    • https://macauroommate.com/ckfinder/userfiles/files/duramezoguravijodiloz.pdf
    • http://hansungid.com/userfiles/file/27975308887.pdf
    • http://gleb777.com/fck_upload/file/ribovidozomexenuxokasak.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=android+1+com+mod+game
    • 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_off0000b613.bin
438033a7647219f9195f4ded26dba60ff874c8c5ca141e0ce542437e8da42f02
pdf-font-stream PDF embedded font (sfnt) at offset 0xB613 10436 bytes
font_01_sfnt_off0000cd80.bin
205651502c49e7ee6cd163f8fa1a414097bb4954255a850f5761428221f86fd8
pdf-font-stream PDF embedded font (sfnt) at offset 0xCD80 17176 bytes
font_02_sfnt_off0000f8df.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF8DF 16792 bytes