Malicious PDF — malware analysis report

Static analysis result for SHA-256 38b861ba953b02a6…

MALICIOUS

PDF

79.3 KB Created: 2021-06-14 03:56:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: 44b2fda10d8801fbd3f84b39365bf6ab SHA-1: 11bb0169bc63b0899ecfd7cac4280d657a36ed61 SHA-256: 38b861ba953b02a6846855b3a69b9986a0199e63b55b4100c66dbd093c39d26d
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to compromised CMS upload directories or are structured as link farms on disposable hosting. The document body, though heavily obfuscated, appears to be a lure related to an 'EKG book'. The primary attack pattern involves directing users to external, potentially malicious websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://infrive.ru/uplcv?utm_term=the+only+ekg+book+you+ll+ever+need+pdf+reddit PDF link annotation
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/202e746f044e99dfbce96a9782c82be2/33707409949.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b972e315966---woriwiporadojivasaxomuzag.pdfIn PDF document text
    • https://forcechicago.com/wp-content/plugins/super-forms/uploads/php/files/dfaec1f15579741626c1fcc701fddc67/88172174746.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/8444371921.pdfIn PDF document text
    • http://bachova-terapia.sk/images/file/jokig.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ac4b432a9a---90901010656.pdfIn PDF document text
    • http://thegioidahoacuong.com/uploads/image/files/gigisixu.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606d50d568faf---48767550981.pdfIn PDF document text
    • http://efrex.cz/files/file/galefa.pdfIn PDF document text
    • https://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/i6gl0nvirbrchmi0msht2jjcnt/66097795067.pdfIn PDF document text
    • http://n2nlah.org/UserFiles/file/fariwujepimidirareduf.pdfIn PDF document text
    • https://purebodycare.courses/wp-content/plugins/super-forms/uploads/php/files/f36qfdb0pno2kp0fjbhoaqvjr6/tugikakitadixo.pdfIn PDF document text
    • http://www.dramayaramendes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16070ae2ecb7ca---jazipolebiwegeluzajuli.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ac44caf5bc---35128733105.pdfIn PDF document text
    • https://lee-trading.tw/archive/upload/files/bavira.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e1b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1B4 5112 bytes
SHA-256: dfaab2074e572d4734267325781f71422f343d37b5f22b470fd9390f7fa65be2
font_01_sfnt_off0000f315.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF315 1800 bytes
SHA-256: e9a5a1f6ed95b1e3669933bb00002ad32a1708c3e0b735191cad5e02368a6c7d
font_02_sfnt_off0000fba3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBA3 10548 bytes
SHA-256: 1de1a41c5a58fe3007dc2c8080ebc9dd30bbde70d30d30660a73f817e4ad5fe4
font_03_sfnt_off00011f8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F8D 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f