Malicious PDF — malware analysis report

Static analysis result for SHA-256 b379a8155bc0ad9e…

MALICIOUS

PDF

83.5 KB Created: 2021-04-15 22:34:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 3c4086b7523fcb04ad5fd4b3a3f76068 SHA-1: 440d6d3a8f401893e05c778f33c13ee270dc2136 SHA-256: b379a8155bc0ad9eea603586de81f5fce4d3324396d1cdcfdac82e12f04e765a
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to unknown or potentially suspicious domains, suggesting a link farm designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure the true destination of the links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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.termis.org/system/files/webform/nibobuzokojovafizuza.pdf In PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/13471650610.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/xugapovapoz.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/65000750087.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/xixarujopotagateregigo.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/49428740932.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/vogelunejubujapezidugave.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/vonasajevevedatenalezeb.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/31226501773.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/cv9VXjIrmdE/uplcv?utm_term=sans+20+critical+controls+posterPDF link annotation
    • https://drones.princeton.edu/system/files/webform/xakunowegetudirojevogejiw.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/65601020807.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/fazarixi.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/66931006591.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_005_off00012a98.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x12A98 16336 bytes
SHA-256: 15be261b22099586ade56c9ca4d95ec90d5357685a10ab86043662f8c0a79f5f
font_00_sfnt_off0000dda5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDA5 4520 bytes
SHA-256: 0ff50e8c852f948bcf9138d672b02a723b6bbbdfd39f61541572818ed705b13b
font_01_sfnt_off0000eda7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDA7 5304 bytes
SHA-256: f26bb8173211b6ed77e106b791f8c0c9b6c443c3e14f2a6e30533b3f03fe5b79
font_02_sfnt_off0000ffba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFBA 13060 bytes
SHA-256: c6279ce803fe03d394e224f1db30d5b3a0ea2837a2bceb259d72e88b2a438353

Open this report in the interactive analyzer, or submit your own file for analysis.