Malicious PDF — malware analysis report

Static analysis result for SHA-256 42e2b9c5e1671b81…

MALICIOUS

PDF

68.1 KB Created: 2021-04-15 23:04:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 50d25b11b25df00970d9f74c7aa38677 SHA-1: 048d1dd9dee55cb909368c7255d3075dae668e83 SHA-256: 42e2b9c5e1671b81638898bc2d729a392ee07d8f0cb24a74510052bfa02e2afe
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 0.9991

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://ambrose.edu/sites/default/files/webform/mamak.pdf In PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/nuzutigurazuleziwuta.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/11118021720.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/rijuluzevowogadabiwi.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/81826716543.pdfIn PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/razodogodipuvubetixem.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/52499587618.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/38780162719.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/zoxajetuvu.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/goxara.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/kuvusuwube.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/fzgW7-mxBc0/uplcv?utm_term=learn+tarot+cards+freePDF link annotation
    • https://community.princeton.edu/system/files/webform/26098210740.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/sikukuditizituxabisezopel.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/sametuzovu.pdfIn PDF document text
    • http://www.w3.org/1In 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_off0000d4e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4E4 4924 bytes
SHA-256: b9ffe6352292c1e64dadcdc4440261aa72b46ed765d102f9cc2c8d29556df7c6
font_01_sfnt_off0000e5b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5B9 10680 bytes
SHA-256: 9e457666a4b38db0d971026cd8a00fa084fd3d68176aa1e3aba1c6c3ee304a6e