Malicious PDF — malware analysis report

Static analysis result for SHA-256 435a37202a98e4df…

MALICIOUS

PDF

70.6 KB Created: 2021-04-16 05:09:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: 2454149f2c4f6622c56bea15420dfef6 SHA-1: 6f35b2f6c024f460155ec60617d6726bcdce8f48 SHA-256: 435a37202a98e4df4efb930dbd3b049cc38403b95c4f733c4a2eeb0af4789d95
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://vectorcorp.net/sites/default/files/webform/resume/sowasipaxezok.pdf In PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/bukitonixoravutewoluba.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/pibodanagulevegomenet.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/kuvusuwube.pdfIn PDF document text
    • https://architecturaldesigninc.com/sites/default/files/36110977311.pdfIn PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/razodogodipuvubetixem.pdfIn PDF document text
    • https://www.pharoxglobal.com/sites/default/files/webform/7322176875.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/17947704001.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/tatesejozamelifat.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/xaduxiwipel.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/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=gta+5+cheats+pc+helicopterPDF link annotation
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/8342566550.pdfIn PDF document text
    • https://campusrec.princeton.edu/system/files/webform/popikinof.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/lezedatabamivija.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/vijebutipide.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/ninavixokamorul.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/mizol.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_off0000d79e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD79E 5176 bytes
SHA-256: 23b9f386c1786017299dcfa2f2fc738cb12e6751476b2875da2c94ad25b12468
font_01_sfnt_off0000e937.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE937 10876 bytes
SHA-256: e6c37a37d3034fecb0307381bc1b80dd8e2d22e0b00fea0d92d2d31ce6f6b69e