Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4f9d0369030d423…

MALICIOUS

PDF

75.6 KB Created: 2021-04-24 00:33:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: d53b29ea62c70e964a5f6c0847e449c0 SHA-1: 4ad047dfc696133b9545a19d90737d8fd75263b3 SHA-256: a4f9d0369030d423e017cef7151364ab8e1b9055013b5233713ac345ca923001
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://natsihwa.org.au/sites/default/files/webform/degajakuko.pdf In PDF document text
    • http://seiary.com/sites/default/files/webform/rec/jizexatunurometubukos.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/noranixuguwetepefosobad.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/61928937085.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/42416127327.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/fifomibap.pdfIn PDF document text
    • https://www.jsif.org/sites/default/files/webform/54250685962.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/28693943460.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/nuwirofu.pdfIn PDF document text
    • https://www.dgs-interparts.be/sites/default/files/36138637258.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/95133977644.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/jitebetususi.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/BkSY9tpko7c/uplcv?utm_term=maytag+portable+dishwasher+instructionsPDF link annotation
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/sukazejaso.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/86005813007.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_off0000e9d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9D6 5676 bytes
SHA-256: d72f842589d1dad15d749d37ac97a743aa15d350acaf383b9bf95ed8271889a3
font_01_sfnt_off0000fd3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD3E 10464 bytes
SHA-256: d73d658432f7c14685d2ab99267e30890671edecdb95bff7cfe1a75dbe00261f