Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a25d13db89b18eb…

MALICIOUS

PDF

78.6 KB Created: 2021-09-21 03:44:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 27479341e257e2dd4ebebf470560778f SHA-1: 564a6c8b82571de68c7b74e86984a0d1b420f612 SHA-256: 9a25d13db89b18eb51b6c3943f215e80160bbad8cb042147235f9cebd326b815
134 Risk Score

Malware Insights

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

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and external URIs. The PDF structure suggests it's a link farm, with numerous links pointing to external PDF files hosted on various domains, likely serving as a lure for phishing or malware delivery. The presence of embedded JavaScript, though not fully analyzed due to obfuscation, further supports malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://rtm-plus.com/ckfinder/userfiles/files/zosuliwulujigedojek.pdf In PDF document text
    • http://alacarte-design.de/userfiles/file/89890620438.pdfIn PDF document text
    • http://samwha.com/upload/userfiles/file/17672115244.pdfIn PDF document text
    • http://dc-07b6a75bc4d0.breakthrough-physical-therapy.com/userfiles/files/14605713102.pdfIn PDF document text
    • https://finliz.lt/i/File/74596031056.pdfIn PDF document text
    • https://sistemagestiondpr.co/userfiles/file/7833352851.pdfIn PDF document text
    • https://thefencedocumentary.ca/adminfiles/file/furumozamunipunesapivu.pdfIn PDF document text
    • http://chochosanencino.com/uploads/files/doxaxefamaruzutakotopag.pdfIn PDF document text
    • https://globalathena.com/ckfinder/userfiles/files/20616132170.pdfIn PDF document text
    • http://elpijisystem.com/file/nojetemoduferuxor.pdfIn PDF document text
    • http://zygzak.eu/foto_dane/wysiwyg/File/3707891430.pdfIn PDF document text
    • http://thaide.org/userfiles/file/jilogome.pdfIn PDF document text
    • http://caogenzhiben.com/filespath/files/20210908105809.pdfIn PDF document text
    • http://poetische-malerei.de/web/editor/files/68201748985.pdfIn PDF document text
    • https://rotterdampools.com/contents/files/97667746994.pdfIn PDF document text
    • https://itscebu.com/upload/file/20210903155914.pdfIn PDF document text
    • http://ottotech.center/userfiles/file/27469673076.pdfIn PDF document text
    • http://d-a-s.cn/userfiles/file/molezeridigokaxat.pdfIn PDF document text
    • http://bivalyracing.hu/files/file/90358877317.pdfIn PDF document text
    • http://fge-service.com/userfiles/file/tapozusorek.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109151144562442.pdfIn PDF document text
    • http://gold-carsales.com/js/upload/files/fitifesamerosotuvifem.pdfIn PDF document text
    • http://hyundaihungthinh.com/uploads/images/files/xujovazepopox.pdfIn PDF document text
    • https://posh.hr/files/44607510970.pdfIn PDF document text
    • http://www.mueblesgamez.com/ckfinder/userfiles/files/41807961224.pdfIn PDF document text
    • http://precedent.by/_newsite/images_from_html_editor/file/diwolarixarapixum.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=mass+effect+3+androidPDF link annotation
    • 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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cefd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEFD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e714.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE714 10588 bytes
SHA-256: 2c25ec4ec5f744399d397a59006b2463be3f4c5a432869f9ceccb660f03011af
font_02_sfnt_off0000ff70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF70 17480 bytes
SHA-256: 37e85e828944a79592835153ab44b90470e39111eec007bc817c3711f64785a3