Malicious PDF — malware analysis report

Static analysis result for SHA-256 842da72f3bc55bed…

MALICIOUS

PDF

87.9 KB Created: 2021-06-18 23:21:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: af3f1b77c81627a2a6182a09caafa988 SHA-1: 5b2c33134cff71de53d3b0e2da2f48338aaf003c SHA-256: 842da72f3bc55bedf59e233c8cd800c564df926db16983798bb42c0450038a70
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites. The ML classifier strongly indicates maliciousness, and the heuristic firings confirm the presence of a link farm on disposable hosting. The document body is heavily obfuscated and appears to be junk data, suggesting the primary purpose is to host these links rather than convey information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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=elemental+bow+build+iceborne PDF link annotation
    • https://www.basur-tedavisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160753b602bd30---sakowibo.pdfIn PDF document text
    • https://hiampelectric.com/wp-content/plugins/super-forms/uploads/php/files/c046e3eed572ea7a867fb054a540836f/25766150490.pdfIn PDF document text
    • https://activepymes.com/pub/file/fugoranavipirafizi.pdfIn PDF document text
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16084bcd9d4933---91752827921.pdfIn PDF document text
    • https://manuscripthandler.com/userfiles/file/lavubipajodedetatubag.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e4bd0cbe6f---wamimiwesizusitefinot.pdfIn PDF document text
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/avj5knkvseaqggqaokfk167rvi/97252454201.pdfIn PDF document text
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/7ncgscd8187e4tin1hj9qaed0d/pijez.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/64f062a3b18be27e9fe7347519e98f7b/zixobelitudarudefawa.pdfIn PDF document text
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/79eeddbb2f1796a282f3df790a901a96/21921635356.pdfIn PDF document text
    • https://majorsagilekvaros.hu/uploads/file/48521011801.pdfIn PDF document text
    • http://alfavit.tv/userfiles/file/pudiwibirolotivexifarave.pdfIn PDF document text
    • http://www.rkcomdesignservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607337b4e49fe---kojugoraf.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160829cd7b8ba4---30005036945.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
    • 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_off000101cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101CD 5096 bytes
SHA-256: ce228437b2e2c2519c47b9f110f404511d7c97ba9570d651b2c5cd54035c47e0
font_01_sfnt_off00011319.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11319 12144 bytes
SHA-256: d3a7c4605aa0e2d22119d3a5475416bc09d38536594bff4b378e550edec04811
font_02_sfnt_off00013c28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C28 16148 bytes
SHA-256: d9287914d2c748943582e4502a352cf99ca7f797b2f387c8159471dde55552bd