Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d1c1d28e3321627…

MALICIOUS

PDF

79.7 KB Created: 2021-04-16 23:37:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: bed9bd07d84e11762a0ca770daff983c SHA-1: c88acec99cf72e975a8f84224dd038d976b21b5b SHA-256: 4d1c1d28e3321627a983d40dc01f6747ba1c5b7fc48c9bbf2d1774e696bb7833
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which are hosted on seemingly unrelated domains and are likely part of a link farm designed to obscure the true destination. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically phishing. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it is designed to redirect users to malicious sites, potentially for credential harvesting or further malware delivery.

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 https://www.termis.org/system/files/webform/manejuwavujegajejumoxak.pdf In PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/71502920023.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/larigujumikanezazezogiwi.pdfIn PDF document text
    • https://www.newburghgroup.com/sites/default/files/webform/resumes/talazeleravu.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/ratasivovo.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/20598750849.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/wofofokarawivuboniju.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/27017481005.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/28695523124.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/bulurifabisiwotubavigivos.pdfIn PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/kivalin.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/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=caracteristicas+de+los+modos+de+produccion+capitalistaPDF link annotation
    • https://thesanfordschool.asu.edu/sites/default/files/webform/20850651402.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_off0000eb3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB3F 5124 bytes
SHA-256: e5ee61ced8399d2d5111389f9601b6c08a97c60f666f39b9ef202e2fd410369e
font_01_sfnt_off0000fc8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC8F 11408 bytes
SHA-256: f6aa6671d37fa490255ffa053cbab41239255c4e63dd628f03c8438a02857b7d
font_02_sfnt_off00012187.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12187 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3