Malicious PDF — malware analysis report

Static analysis result for SHA-256 b91a340ee08351de…

MALICIOUS

PDF

84.0 KB Created: 2021-06-15 11:20:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: e712f1fd02d52db6fcdad882678dee97 SHA-1: 9b5b1586c5aebc5514cb4a661b353a9b81f1b20c SHA-256: b91a340ee08351de9f7ca73354f93c139b232076049a1bde16a7ece9a7d80f99
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and links to compromised CMS upload storage, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and does not provide clear instructions, but the presence of multiple links to potentially malicious sites is the primary indicator of its attack pattern.

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://catamma.ru/uplcv?utm_term=typewriter+preset+premiere+pro+free PDF link annotation
    • https://anmimar.com/royal/userfiles/file/47526998832.pdfIn PDF document text
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160887847bb128---21699734025.pdfIn PDF document text
    • https://gastrotest.co/ckfinder/userfiles/files/kajeja.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/c599621c9c87989ee9949be24cffcf78/23614549334.pdfIn PDF document text
    • http://rsst77.ru/upload/files/baxekifaxobiwetitegidawon.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbab2fe65de---zumerajojaravuvoke.pdfIn PDF document text
    • https://bluebeakbranding.com/wp-content/plugins/super-forms/uploads/php/files/dd3db29576f9c976cdae8ce5f424e41a/nowizoxaparidezisene.pdfIn PDF document text
    • http://mosjob.ru/images/file/41429371397.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d2053ecd30---46985219047.pdfIn PDF document text
    • http://www.dismaplant.com/ckfinder/userfiles/files/57797985666.pdfIn PDF document text
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160a69fc9cd8c2---17366447096.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/a56c7su90kubhegvqri4etotdd/degekuwonup.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/16095406aecbcc---napapake.pdfIn PDF document text
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/7m3r23c966pq02h0md1ivml14i/46752776326.pdfIn PDF document text
    • http://srividyaastrology.com/userfiles/file/zazik.pdfIn PDF document text
    • https://mkting.com.co/wp-content/plugins/super-forms/uploads/php/files/26b40ec4173d8700d3f4345571666291/27783203425.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_off00010f2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F2C 4948 bytes
SHA-256: 8c7ca4d94e3351d9cd0d3d22e806f67ea13e32641e32ce8e16e4a8b1788d9116
font_01_sfnt_off0001200a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1200A 10128 bytes
SHA-256: 4d8b0da937a771670dd2dab8be5f2c9f8832faf60e5caf12985ac985d56ba420