Malicious PDF — malware analysis report

Static analysis result for SHA-256 b26d5c5a91097b7f…

MALICIOUS

PDF

99.0 KB Created: 2021-06-22 21:29:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: b5c51b94ea80f28957d022ee68d02fa9 SHA-1: 6dcd1a40d77f20fa0741b746fa1fb773ace33ea8 SHA-256: b26d5c5a91097b7fd7fc62e3e8bb66f69c44d7cbeb6f1e8004976061cbc476ba
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or malware distribution attempt. It functions as a link farm, containing numerous URLs pointing to compromised websites, likely to lure users into downloading further malicious content or submitting sensitive information. The presence of multiple external URI heuristics and link farm indicators supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://inwebjor.ru/uplcv?utm_term=cdi+flexible+furler+manual PDF link annotation
    • http://biancoacolori.it/userfiles/files/92644353453.pdfIn PDF document text
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081d37f76bd0---ruzijowawuji.pdfIn PDF document text
    • http://lesen-und-schenken.de/userfiles/files/10399089349.pdfIn PDF document text
    • https://pablohernandes.com/wp-content/plugins/super-forms/uploads/php/files/124857d76e233e4534f2c2c7f001d8ed/173375315.pdfIn PDF document text
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/6d6ecfabb4c453fcf8d46806811726ac/86831051860.pdfIn PDF document text
    • https://fundreamz.com/ckfinder/userfiles/files/gedujipazoduwutu.pdfIn PDF document text
    • https://londonvipchauffeur.co.uk/wp-content/plugins/super-forms/uploads/php/files/8177cfa00eac9263b8af6462afdc6133/25736035508.pdfIn PDF document text
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608df724d78a4---37993308861.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092e4ea947e3---93099194429.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8b429cfa6f---jilutu.pdfIn PDF document text
    • http://pvsystreports.com/wp-content/plugins/super-forms/uploads/php/files/osvdsggb6t05p6glm9mbkhrna0/13823808522.pdfIn PDF document text
    • https://flexrocksrollovers.com/wp-content/plugins/super-forms/uploads/php/files/mnr02evmg7cu4ep7m3bbng5u18/56869377031.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ae5f55f36d5---64154102149.pdfIn PDF document text
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086c89566f16---72014690842.pdfIn PDF document text
    • http://transbur.ru/admin/ckfinder/userfiles/files/kesutopavoteniduzegiba.pdfIn PDF document text
    • http://stevis.cz/files/file/rewarofotubiziwuralo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013711.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13711 4796 bytes
SHA-256: f94d5aeb543bf7c8de874579b3a826153e62f00b9392708c53c7e4b9ef119090
font_01_sfnt_off0001473d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1473D 12200 bytes
SHA-256: 1317156615e8276dbd1405141e5b0edbf5b2f5d23a8f7c6a656311a334dd03b7
font_02_sfnt_off00017093.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17093 4324 bytes
SHA-256: ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3