Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a691fd0b7ebf24a…

MALICIOUS

PDF

68.4 KB Created: 2021-04-18 16:07:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: 810c6e5c44ffc1c7d0d58b734639273b SHA-1: dc73620c8a7183de8a47b9ee0f351bbd2a76f3a8 SHA-256: 1a691fd0b7ebf24a65b55e7461f52ae1fa3642df8001e275691dd603bf64f26e
126 Risk Score

Malware Insights

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

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

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://cicatsalud.com/html/sites/default/files/webform/17654710786.pdf In PDF document text
    • https://www.jwico.com/sites/default/files/webform/pagijan.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/25680057182.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/jedirokadezat.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/48103714077.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/89737617204.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/42416127327.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/ranet.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/dofivefodazewinewes.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=mr+coffee+machine+clean+light+blinkingPDF link annotation
    • https://www.vub.be/sites/vub/files/webform/piwolumubixu.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/44438097533.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_off0000d024.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD024 5328 bytes
SHA-256: 5d199d3598030ffdc0908f92b059ccf35e43fda3456759f58b5839dd9a8a0456
font_01_sfnt_off0000e22a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE22A 10196 bytes
SHA-256: fede87d38b58e5e82339c72f83450e4d8d749fd92b48342a8d9f7b7e25d861d7