Malicious PDF — malware analysis report

Static analysis result for SHA-256 522c4c5a52b000b8…

MALICIOUS

PDF

75.5 KB Created: 2021-05-25 14:01:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-27
MD5: 596938c199a0d1cbe42adf8a5c86ccc6 SHA-1: be108a1345ae1f64ca42c8f50f82a188a50dd874 SHA-256: 522c4c5a52b000b87dab74c9b14fa9aac649b28b7a4ac3363ce82c7128fb9325
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, pointing to numerous URLs hosted on compromised CMS upload storage and disposable domains. These links are likely designed to redirect users to phishing sites or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7a0f7abe05---najekurumikuzosipetizita.pdf In PDF document text
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16080ddb44c527---xabulokaterep.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/16083123f3aa8c---daxalebojezamunenojoxif.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/i4o4tp5qp0gbjtg4flk7gc0pg1/27610244671.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/1609e42f51baa4---30519470628.pdfIn PDF document text
    • https://truck-diagnostic.ru/wp-content/plugins/super-forms/uploads/php/files/11c48430efa5dae6bb8eeed404638299/80877115935.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/bf5b6cbd884753bebe2eea66b9782457/pebowobovajadosimij.pdfIn PDF document text
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/a06cd3d3acec74ab34389dfd876832f8/41568720552.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16099fe8e38c34---4996785039.pdfIn PDF document text
    • https://contabil-fiscal.ro/mm/file/pitowiturazegizezenuwi.pdfIn PDF document text
    • https://seataclighting.com/wp-content/plugins/super-forms/uploads/php/files/dfcef3d589e9b00cd59bcb248da7e8e4/49477666254.pdfIn PDF document text
    • http://jhferry.com/data/fckeditor/file/%5C/malawamujerafulukurifibod.pdfIn PDF document text
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/5f16a86475cd04a1d13aed27b80530fd/tenozunafikod.pdfIn PDF document text
    • http://akgikorea.com/file_upload/fck_upfile/file/6487211523.pdfIn PDF document text
    • http://aaaexpressheating.com/userfiles/file/22376671336.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=sociedad+y+adolescencia+erik+eriksonPDF link annotation
    • http://lovewhereyoulv.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/8208c812ab49bf6a16aac553c3bf6259/zazawubisodelimok.pdfIn 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_off0000e728.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE728 5204 bytes
SHA-256: 58cd6421cba883270435c1bf7e786d60a92a5fc1d0d7376332911fabdaf07a22
font_01_sfnt_off0000f8ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8EF 11920 bytes
SHA-256: ac3bf31fc67de495a025698e58e45d26bc68b9bafae35d92017e7e570a73ee3c