Malicious PDF — malware analysis report

Static analysis result for SHA-256 66555ae444d9cf48…

MALICIOUS

PDF

99.0 KB Created: 2021-06-20 23:13:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 3addd3e4f5c0b75dba3b6e9b13935318 SHA-1: 8b1b3608ed038300b3fddf811e6cd528c7024c5f SHA-256: 66555ae444d9cf48785bf30d5fa761acaf2cdc89adfb7c8faec410bedb852165
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised websites and disposable hosting, indicative of a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. No scripts were extracted, but the presence of multiple compromised upload links and a link farm pattern points to a malicious document designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/bf74786334c21d9758aae8950801bf24/zufuv.pdf In PDF document text
    • http://nesthomes.in/userfiles/file/fupukanidituzaponobobar.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/dibazelubusoj.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/7c0cdea04825108d14e6a034cf9b2b62/21129319391.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/unqssapojlscp26bi5k6jn4qv0/busajun.pdfIn PDF document text
    • http://bajcsidavidfoto.com/_user/file/fevidawatepapapok.pdfIn PDF document text
    • https://endoaccessories.com/wp-content/plugins/super-forms/uploads/php/files/06quhr7h7rkbo9aondjaiq527l/milemejobuzamij.pdfIn PDF document text
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606c6c417f6f9---12499382420.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a6803bbbfad---zerubojinit.pdfIn PDF document text
    • http://covinahigh1980.com/clients/1/14/147ee80f0cf2e08ca1b5067d21485a43/File/xobefujagix.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c7b7c504bb9---30715325789.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607325e82ffa0---83154906554.pdfIn PDF document text
    • https://campermagazine.tv/public/file/rozura.pdfIn PDF document text
    • https://ludbaegitim.com/calisma2/files/uploads/42264223414.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a7fb909a78---78863830265.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=sai+baba+songs+by+spbPDF 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://scripts.sil.org/OFLIn 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_off000131a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131A1 5204 bytes
SHA-256: c9ae4e143e72a4c443e9061df61c2495c5c1beda3bc78c6db19e53d1038a9246
font_01_sfnt_off0001436b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1436B 11132 bytes
SHA-256: c0cfddcec8b789aa3b689f0724b7fee49cf73e602de8b19582dcbb6f6431d35a
font_02_sfnt_off0001698f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1698F 16332 bytes
SHA-256: 87c1b78372edd156ea3ecf5880dc6aecf92b7b983aadb838ab3a270a0a69396b