Malicious PDF — malware analysis report

Static analysis result for SHA-256 28cbdb3c56e7e942…

MALICIOUS

PDF

83.4 KB Created: 2021-05-14 23:08:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: b2dc720c09cb7bbbd90e4a393eaa1679 SHA-1: 0af9e89f33a71a7c77e15f9143e1d3c5e2897a71 SHA-256: 28cbdb3c56e7e9428dce6404f96fcba2c6fb2cd824d8528b1bc084429bc4b0e2
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://cal.lighting/wp-content/plugins/super-forms/uploads/php/files/62df01b2a159f1ec388309d63dcd7b47/65843042881.pdf In PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160769e3ad4ea5---kilokinanekekupesekamusuj.pdfIn PDF document text
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ab59019b2d---3036576693.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c9fe00552a---rosofekomoxesepuwimoxexu.pdfIn PDF document text
    • http://ubest.ru/images/file/netalogalalosobisi.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/160762289aea5f---96602733585.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/16070e9b02f7aa---4743479966.pdfIn PDF document text
    • https://actor-conseil.com/files/file/73206162223.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608f8127ee356---tumumixa.pdfIn PDF document text
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/o5oltprphtdpvpshkgl63h6qv5/86573540457.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160942776a6e3d---17488908256.pdfIn PDF document text
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/4e4lus6qnf66bsgsg7rmqup6q2/40327303169.pdfIn PDF document text
    • https://spectrumohio.com/wp-content/plugins/super-forms/uploads/php/files/72ac40924d01967f28e6e3f4ed04ab3c/jatamuso.pdfIn PDF document text
    • http://dobryremont.pl/ebobas/portal/app/webroot/img/tmp/file/16209259762819.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/013ff791c39fb26073493a160b76ae50/bafifulafufibokejisabata.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/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=windows+form+application+l%25C3%25A0+g%25C3%25ACPDF 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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d6fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6FD 4124 bytes
SHA-256: 295e903d5f63d98ff50f036ab2663369110a4b2af0e573b72268db2983812824
font_01_sfnt_off0000e59a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE59A 5868 bytes
SHA-256: 5976d25c855963355c65560966de68434a798e9b85e8073c027f844ee1dad364
font_02_sfnt_off0000f900.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF900 17552 bytes
SHA-256: ccc90e14cc2b92bf10671a04012fc700649b885c89b457cfa7c1d707c6a41423
font_03_sfnt_off00012722.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12722 16396 bytes
SHA-256: ace49ff19ece63738b623dabdc7ea46d2145f4cb4769ef6cd7e76d485eb5e4fb