Malicious PDF — malware analysis report

Static analysis result for SHA-256 636a0dfaf83b555f…

MALICIOUS

PDF

73.0 KB Created: 2021-04-21 03:06:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 1045e9836b10b53ece9a4b7cfb7d9c13 SHA-1: 565f528a9a8cdccc0f2a16a0edd4781dd43e7079 SHA-256: 636a0dfaf83b555f0757466c83e947398b59d5d70407a30f2752abd2f32ef34b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV detection, indicating malicious intent. The document body, though heavily obfuscated, contains references to 'Doubledown casino vegas slots free chips', suggesting a lure for gambling-related phishing. The presence of numerous embedded URLs, many pointing to seemingly unrelated domains, aligns with link farm tactics often used to obscure malicious destinations or distribute malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/96392425525.pdf In PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/bugoxugokerudanetisene.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/30106672217.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/zarogoluvesiriwameb.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/subeditanutojodojewogize.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/12938533755.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/90077644064.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/87706268510.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/31626011693.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=doubledown+casino+vegas+slots+free+chipsPDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/68272747422.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/mevupuxapiledowitire.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/dilitopuwivane.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c8b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8B1 5592 bytes
SHA-256: a0d05c8ff1304bd10fa3c039d9cc85b343f9ee7292a3afb56d983d12d18431d4
font_01_sfnt_off0000dbb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBB9 13656 bytes
SHA-256: 36859e3d821c360e24e4e8463506594482971cc185164f8f8e3558db10f5aa66
font_02_sfnt_off000106c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106C6 4324 bytes
SHA-256: ce7e2e230a41ba6fc2d7d2240890c8289d67876d84a3d076d67c0b48111c8230