Malicious PDF — malware analysis report

Static analysis result for SHA-256 641dbac8056cac9f…

MALICIOUS

PDF

79.9 KB Created: 2021-04-27 15:11:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: e1534de28d8eca8fd3ff65a940152da1 SHA-1: df230dd2a2012b8549c0dbdd160dd7252c49e414 SHA-256: 641dbac8056cac9fa17f50a8ebb3baa5f535b19577cfcd50a2c8987c24b67e3c
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to unknown or potentially malicious domains, suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of techniques used to redirect users to malicious sites.

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.natsihwa.org.au/sites/default/files/webform/72789215659.pdf In PDF document text
    • http://seiary.com/sites/default/files/webform/rec/kutovaduro.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/bofuwidesuxugebogaxa.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/9555400870.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/susumijifiwef.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/96392425525.pdfIn PDF document text
    • http://spotlight-sites.com/sites/default/files/webform/40861703051.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/jowodudarazobipadumalo.pdfIn PDF document text
    • https://www.afscme65.org/system/files/webform/fabituwinuxofi.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/27017481005.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/zMnd8XtcwSM/uplcv?utm_term=what+size+embroidery+hoop+do+i+needPDF link annotation
    • https://drones.princeton.edu/system/files/webform/dovekilubexuvizufak.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/76225898136.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/liwubuwivak.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_off0000fcac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCAC 5472 bytes
SHA-256: 634a63b701ee04d78a3a8b29aeae17faf55cba5bff443ad978bfa50842ad5196
font_01_sfnt_off00010f2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F2C 10540 bytes
SHA-256: e46b69029f230e006d515a633e9b9e7f37f767346d7c9db71356d67fd75b7ca7