Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4b9bdc7603d43a9…

MALICIOUS

PDF

72.6 KB Created: 2021-09-11 02:52:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 5eff3454c8753f9c71b106a35e4ca3a7 SHA-1: edc686f4033773590b6a1d81c9d6b8be084cf341 SHA-256: c4b9bdc7603d43a9a6269999f8f73edf21e31fcb05fa8ed0ce5bba2734d23953
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. The presence of multiple external URIs and link farm heuristics confirms the primary attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://catamma.ru/uplcv?utm_term=android+weight+tracker PDF link annotation
    • http://amoy-art.com/Upload/file/89545303442.pdfIn PDF document text
    • http://bushurov.ru/images/files/37494547964.pdfIn PDF document text
    • https://cedria.es/DOCUMENTS/FotosFCKEditor/file/5061738662.pdfIn PDF document text
    • http://phuvuongcorp.com/luutru/files/zadenulopoxedixa.pdfIn PDF document text
    • http://top1np.com/ckfinder/userfiles/files/ragafefiniwepinitupaxav.pdfIn PDF document text
    • http://vibrobreaker.com/files/files/xituridobuwarabuvumusaxil.pdfIn PDF document text
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/334767b92dbc0ceaf33f3e602ae07886/dosawebubimatugoxapamel.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613124a2b32f5---32756579055.pdfIn PDF document text
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/qecv63ijuftpmkj97be8irgcrv/78854534601.pdfIn PDF document text
    • https://snqrsl.quebec/upload/editor/file/mepuzu.pdfIn PDF document text
    • http://carbontuning.ru/file/71391915382.pdfIn PDF document text
    • https://windsbs.biz/files/file/zozagoxomobabum.pdfIn PDF document text
    • http://videotour24.com/data/fckupload/file/24848694907.pdfIn PDF document text
    • http://thucancakoihikari.com/luutru/files/netuzafemazawuk.pdfIn PDF document text
    • https://mimpishio1.com/contents/files/24522440707.pdfIn PDF document text
    • http://fundacionecla.org/resources/original/file/dobabeleleniwidil.pdfIn PDF document text
    • http://uptindia.com/newsimages/file///rurilitovadamino.pdfIn PDF document text
    • http://world-housing.jp/ckfinder/userfiles/files/95529749175.pdfIn PDF document text
    • http://neoneophytou.com/ckfinder/userfiles/files/wokerikefigeledujavet.pdfIn PDF document text
    • http://studiotrusso.it/userfiles/files/wojebevikapexeje.pdfIn PDF document text
    • http://mabo-meccanica.eu/userfiles/files/19777310279.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/b669121a825895f003ae33df3713f9c4/66229474544.pdfIn PDF document text
    • 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_off0000bb85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB85 10596 bytes
SHA-256: f72418d5192a71b2ed9d249019b6b31256406100c169f5c62a059cccb31d51d5
font_01_sfnt_off0000d38a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD38A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000eb9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB9C 16156 bytes
SHA-256: 79e97ff6f5a275de2dae55ebf9a41df65d6b3dde8c94d6f87284764b72e206d8