Malicious PDF — malware analysis report

Static analysis result for SHA-256 13a1937c0d5d4369…

MALICIOUS

PDF

76.4 KB Created: 2021-06-25 09:01:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-14
MD5: a9f82a32ec31e5d23cd815a17e9d46c4 SHA-1: 4e7c87b59959b15073b0dbdf1a5d017dfca44f22 SHA-256: 13a1937c0d5d4369f9531877bccd7fe10c083680714afe0192625798150247ed
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress sites, likely intended to host malicious files. The ML classifier strongly indicates maliciousness, and the presence of numerous distinct hosts hosting similar file structures suggests a coordinated effort to distribute malware. No scripts were extracted, but the overall structure points to a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b6120db6a34---24745861195.pdf In PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160846fd26a771---vexow.pdfIn PDF document text
    • http://faurerom.com/userfiles/file/50791574142.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/160be6bfb2dccf---tesutuwivuwigusubo.pdfIn PDF document text
    • https://asset-books.com/userfiles/file/53812769938.pdfIn PDF document text
    • http://rocb-ap.org/file_media/file_image/file/patolarinixibibusatulot.pdfIn PDF document text
    • https://nestaerospace.com/uploads/file/saduj.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/160788ef18ebdb---79107930145.pdfIn PDF document text
    • http://adabaskimerkezi.com/upload/file/14177623968.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/i7udb42aal6aqpthij0m7liab0/fupidoko.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/k045aofosqif7bv729r6r095e4/kubevomibapixotimixu.pdfIn PDF document text
    • http://hi-techfiber.com/userfiles/file/37259485855.pdfIn PDF document text
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/a157a9025cff074f30e3364a1096ec4a/tujowasobigubaka.pdfIn PDF document text
    • https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/8f57454d2fa378ac7faf9856c101e158/fekeve.pdfIn PDF document text
    • https://whitesal.com/data/images/file/5370_20210625023016.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099a73825bc2---24361205772.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/n34i8d08jan7ifsiq0ko4cpfm8/jalaxerevuwevoxipipov.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/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=hall+of+fame+manualPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f062.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF062 4600 bytes
SHA-256: 22fb6214816b6e4da7499da89b4df4e97ec3098d06610b0afb18b5265a7c1bcf
font_01_sfnt_off0000fff7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFF7 10988 bytes
SHA-256: 9a079d1b96b6c54a6184bd0b0abad9923752bc5fb0117aa0754af6dd89198e1d