Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5f6b763a190ea93…

MALICIOUS

PDF

70.7 KB Created: 2021-10-01 14:21:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 33fa8ea9c970f0556401560e7067d068 SHA-1: 52e769d116e1d035fa8f9d7224dcbf88e65b5fb1 SHA-256: a5f6b763a190ea93b7ec788171f6e96c1cc5b49f6cf9ea3f264c2bc8ef755007
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites and disposable hosting, forming a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple external URIs and a link farm structure suggests an attempt to obscure the final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://paeonia.ch/userfiles/files/tepigokuzogivoravi.pdf In PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/5dc0df1644d6c2f1e82a4773af0b7f14/64869498046.pdfIn PDF document text
    • https://dalton-english.com/userfiles/file/21620629692.pdfIn PDF document text
    • http://westfallassociates.com/documents/file/dowewed.pdfIn PDF document text
    • http://integrotech.com/zdjecia/file/daxapemoxizel.pdfIn PDF document text
    • https://afra24.com/basefile/afra24/files/64626792232.pdfIn PDF document text
    • http://www.perchegouet.com/ckfinder/userfiles/files/nofebefogudanokuga.pdfIn PDF document text
    • https://zhavezbozi.cz/data/file/63075738617.pdfIn PDF document text
    • https://oriolefashion.com/ckfinder/userfiles/files/kegamavepidododoxalem.pdfIn PDF document text
    • https://karlholmbygg.se/UserFiles/files/woropilodupanuxi.pdfIn PDF document text
    • http://nasfthr.com/userfiles/file/dipivalawe.pdfIn PDF document text
    • http://candybeauty.vn/upload/files/kozezitanodonobubob.pdfIn PDF document text
    • http://tichdiem.surecare.vn/uploads/userfiles/file/34669718059.pdfIn PDF document text
    • https://dammesliepas.lv/ckfinder/userfiles/files/xirenatewaginuvusuwun.pdfIn PDF document text
    • http://mwbright.com/upload_fck/file/2021-9-6/20210906133237169697.pdfIn PDF document text
    • http://kadh.kr/bobod/upload/file/28576555868.pdfIn PDF document text
    • http://webbyshoe.com/fckeditor/userfiles/file/doxoniwurudanukumazazowo.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613399b456179---56398140894.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/3168891ae31a03a661810d32f09a7bb5/zukutegexix.pdfIn PDF document text
    • https://sibiucuratenie.ro/fckeditor/userfiles/file/bimukurevomirironis.pdfIn PDF document text
    • http://qdsenfeng.com/data/files/32839528928.pdfIn PDF document text
    • https://tworaise.com/userfiles/file/28026562876.pdfIn PDF document text
    • http://hertzlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/69923556126.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=uhd+4k+iptv+apkPDF 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_off0000b295.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB295 17404 bytes
SHA-256: d0a3ec7745475aedd241da30458f8476121c2ab9af65e780c526840ffb7ca6f4
font_01_sfnt_off0000de97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE97 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f6ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6AE 10064 bytes
SHA-256: 4a82c92296c05a26cce1e2c77365bcd6391325f8f2dd7af564b2bf55bef6622f