Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ef8568b782dd84c…

MALICIOUS

PDF

73.2 KB Created: 2021-04-14 00:28:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: f0ab6c1e3f40ef8f17cc26bcc13bb9bd SHA-1: 12537ea76ec607359372cdf44f83b0e37c5130c7 SHA-256: 4ef8568b782dd84cbee13fa9e103df52b407161c5e67c2035b218dc03ee6327f
126 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded links, many pointing to disposable hosts, suggesting a link farm or phishing lure. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it is designed to redirect users to potentially malicious websites.

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://www.osgeurope.com/sites/osg-corporate.dev/files/webform/fifomibap.pdf In PDF document text
    • https://www.uts.cw/sites/default/files/webform/89737617204.pdfIn PDF document text
    • https://www.termis.org/system/files/webform/vomijalikuwukilowerosi.pdfIn PDF document text
    • https://natsihwa.org.au/sites/default/files/webform/kixeje.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/tizagoge.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/84972388600.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/86947183128.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/fulakosilukubusovugatupus.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/povufukawonafano.pdfIn PDF document text
    • https://www.newburghgroup.com/sites/default/files/webform/resumes/woxofenobe.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/xexazud.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/43403042061.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/dufadurelabakugozuku.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/kafavepovimurajubek.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/YTWXjIUwRh0/uplcv?utm_term=incremento+y+razon+de+cambio+derivadasPDF link annotation
    • https://www.healthdata.org/sites/default/files/resumes/muvebijamalixodimobowase.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/61493424170.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/26360011081.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/68272747422.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_off0000dc2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC2C 5344 bytes
SHA-256: 89b725e1fdbd91ee44b5123f7575a335e7977a2a492c69245e8c146091c89926
font_01_sfnt_off0000ee50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE50 12232 bytes
SHA-256: 48a1b46f0a41cfd3b5e9274aa8b05a6b595e756692ec4df0b6ba9b47351e9439