Malicious PDF — malware analysis report

Static analysis result for SHA-256 d425c0ea89b26f63…

MALICIOUS

PDF

73.2 KB Created: 2021-06-14 15:38:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-04
MD5: 8c46e893d2c486f0e1d122bdd2cc6b5a SHA-1: ec33ec057e8b6c1f09e27a7a18226401c01614e2 SHA-256: d425c0ea89b26f63eb2cb61795bb2ebb7c6da5f4bf550bb7320fc1515c91f20f
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://krisoc.ru/uplcv?utm_term=someone+u+loved+piano PDF link annotation
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/9022410f69b5474586aa826e883bbb7b/18548237860.pdfIn PDF document text
    • https://atphp.ch/userfiles/file/55298779726.pdfIn PDF document text
    • https://dixietemporarystorage.com/wp-content/plugins/super-forms/uploads/php/files/0983cab58ebfe6f3ac890623cd16dea1/burimuwawekeg.pdfIn PDF document text
    • https://baatco.com/ckfinder/userfiles/files/bakuwopu.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af7e6bcb356---xeten.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/8b96a2cfe4c50cdb5b5cdfcff362e1d0/winubugakapi.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/160785e0e97473---guzaduvinixilibuva.pdfIn PDF document text
    • http://apexhealthnutrition.com/newerac2c/userfiles/file/67355785987.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/19a4a9a259e4fa4c7dcccd7b660f0712/12701958481.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/nem2h04j53hc2b0nmjg1vqge1n/xapafitebeniveropebafeneb.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/nirojujixudiwoxivuzo.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609282861fdd9---nepimenuxijudubemewizako.pdfIn PDF document text
    • http://archerelectricsupply.com/userfiles/file/28820023819.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608d9fdec8c4d---32601001315.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a797c2d31f0---gamubamujizavexido.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e139.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE139 4996 bytes
SHA-256: e2a559f5481af3187f334e385585b0a890ba478081b11c7284aa35506931ebf7
font_01_sfnt_off0000f22f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF22F 11100 bytes
SHA-256: b30efbfb1e07b4b6f47863d0ab9edf6ef511dbbffc6a9a9f074c6d0e7928814a