Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b08d816819896d1…

MALICIOUS

PDF

84.0 KB Created: 2021-06-25 16:30:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: fcd949588ca1883dd7daf762d6256e2f SHA-1: e6fdfd1966b41875856606951a8ed19dea3ecabd SHA-256: 1b08d816819896d14af9ccda92b21e28b9bd75bab68ff66f1a68675ae8c62b27
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a link farm pointing to multiple compromised CMS upload storage locations, suggesting it's designed to redirect users to potentially harmful content. The presence of embedded URLs and the nature of the heuristics strongly suggest this PDF is part of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/e32b4ffa01c63c63b7b644e2caf67951/41990163983.pdf In PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/n4he7cne5uqdf26f09veh94bjt/nozajurobajuvenepapune.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16070f84ee133f---37486989850.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/hcgq46g9pi6ums9ts5ums5u7qk/mivososamumi.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/90894095475.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//voberubizus.pdfIn PDF document text
    • http://brno-skoleniridicu.cz/ckfinder/userfiles/files/97094367203.pdfIn PDF document text
    • http://www.hydro-tg.pro/upload/file/wadudeno.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f28246e173---lokibozudowojononatewu.pdfIn PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b5883ed555---niwuditumireropupis.pdfIn PDF document text
    • https://hsse.cl/files/pevivilovufeleburuv.pdfIn PDF document text
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/a6964da0f99282a879c22e307cc1c165/78287282363.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608d93138eddc---65116185013.pdfIn PDF document text
    • http://elfuklid.cz/foto/Image/file/87627867149.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/ad2ce2ed5dc9d1505e1437c38f007c91/vusujetonijopikete.pdfIn PDF document text
    • http://gemculture.com/userfiles/file/3685093257.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=keith+devlin+introduction+to+mathematical+thinking+pdfPDF link annotation
    • 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_off0000e169.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE169 11148 bytes
SHA-256: a78bca2363588d208b31ff2653a3d5c685366e96a555bacf901410ce4cbe88bb
font_01_sfnt_off0000fb12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB12 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011324.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11324 17624 bytes
SHA-256: b6e7b0541a3a2c53803e9afaf0c076f7f664f153be29a1673e6355ed43a498f6