Malicious PDF — malware analysis report

Static analysis result for SHA-256 3cd1b253e43352c1…

MALICIOUS

PDF

81.4 KB Created: 2021-09-08 08:56:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: a201a95bb59a1cd940d2bc0f9702d104 SHA-1: 041b1fa08e375ba7a7362a018fd2b2c7e48909f6 SHA-256: 3cd1b253e43352c196525169dc33f0e704a43a1fcf0e23e7fd50b1f50df3cfb4
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external PDF files hosted on various domains, many of which are identified as link farms on disposable hosting or compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple links suggests an attempt to broaden the attack surface or evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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 http://fitviewer.de/files/file/lidoxikitekupit.pdf In PDF document text
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/16070b95aec102---jugeba.pdfIn PDF document text
    • http://cosonhuath.com/hinhanh_fckeditor/file/rinakotibajanudalote.pdfIn PDF document text
    • http://zoltysnieg.pl/pliki_wyswig/files/jimigigafavunimowav.pdfIn PDF document text
    • https://alamansyria.com/userfiles/file/jexuvavizozawof.pdfIn PDF document text
    • http://shengyaweb.com/uploadfile/file/2021072003183742.pdfIn PDF document text
    • http://bradzo-ep.com/uploads/files/wimub.pdfIn PDF document text
    • http://syuncyoku.jp/upload/file/47032576743.pdfIn PDF document text
    • https://ddnepal.com/assets/userfiles/files/42550150145.pdfIn PDF document text
    • http://ideviceplus.be/app/webroot/files/userfiles/files/646184217.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c35304534e---reditapu.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/160870d57c865f---lonaxumalapeveveroradise.pdfIn PDF document text
    • https://howardsteeves.com/wp-content/plugins/super-forms/uploads/php/files/d8817d0257db01b9aa90dd29e93a317b/pirilu.pdfIn PDF document text
    • https://hagakure.by/upload/editor/files/norobu.pdfIn PDF document text
    • https://bbmint.com/userfiles/file/buzofere.pdfIn PDF document text
    • https://evg-prague.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a1f9fbb2524---42858076616.pdfIn PDF document text
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/a47d670f7892937715daba80ee5fa1d1/vuguti.pdfIn PDF document text
    • https://bya-ingenieria.com/ckfinder/userfiles/files/jumaxeloratenoju.pdfIn PDF document text
    • http://cheapmarkt.com/userfiles/file/84011643971.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16080347d53d48---96443264534.pdfIn PDF document text
    • http://cinstech-inspect-survey.com/fckeditor_userfiles/file/44560579610.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=wrecking+ball+book+pdf+freePDF 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_off0000d6cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6CC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eee3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEE3 10752 bytes
SHA-256: 71c455e26140f0148b9fd8f1e7b1212e1db8a0aebc8839b29a70f923a10df200
font_02_sfnt_off00010742.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10742 18712 bytes
SHA-256: 7fc31a34400580b4901ef2e5d495a2cc467e88eeec623293ac17359f4ff1e832