Malicious PDF — malware analysis report

Static analysis result for SHA-256 548c89953703b876…

MALICIOUS

PDF

74.7 KB Created: 2021-04-23 13:37:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: fa44c7427ef0fd2f9d9d8eaf7b63e825 SHA-1: 26e5894e64e4ca80104d35e10eae578eb97b51ee SHA-256: 548c89953703b876dfa7300ed2cffbce6af102682fd572a5f55cb1212fb720c6
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 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://www.natsihwa.org.au/sites/default/files/webform/zolevijovexoneda.pdf In PDF document text
    • http://seiary.com/sites/default/files/webform/rec/11252708720.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/80982398497.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/17184396690.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/9979090083.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/78191676466.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/togivem.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/38780162719.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/30106672217.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/piselusani.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/29410319198.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/6948618973.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/65047245793.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/~3/3CAf4wW3hvY/uplcv?utm_term=how+to+change+battery+in+stauer+watchPDF link annotation
    • https://www.healthdata.org/sites/default/files/resumes/sametuzovu.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_off0000e7ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7AB 5324 bytes
SHA-256: e64e2e70dcde31ad40bb2225f0725e9f08cbed0bce3f44a84ea5ba0fb46fa1ab
font_01_sfnt_off0000f9da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9DA 10604 bytes
SHA-256: bd04dd76a71052fa07a2597820db86dc0dafa3e5600f79fcf491f17a162a5829