Malicious PDF — malware analysis report

Static analysis result for SHA-256 53acc2ac39597a6a…

MALICIOUS

PDF

76.2 KB Created: 2021-09-21 06:11:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: dae3311e0644476613e11206f0ab1584 SHA-1: b4d56b7429a48eef84c69d3d6002d24f3a3d4cb4 SHA-256: 53acc2ac39597a6a58003fb80df2c5ed6b1927401a0eeadad600f0b51929c0fd
72 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is often used to redirect users to malicious websites or download further payloads. The PDF also contains a large number of external URIs, many of which point to compromised or disposable hosting, indicating a link farm designed to manipulate search engine results or distribute malware. The presence of embedded JavaScript and the link farm structure strongly suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.3127

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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
  • 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://megashina24.ru/files/files/defuver.pdf In PDF document text
    • http://cochemical.com/upload/files/7229556210.pdfIn PDF document text
    • http://china-engine.net/ckfinder/userfiles/files/vetisogebagimas.pdfIn PDF document text
    • http://4els.ru/uploads/images/files/pokigiwaxakiko.pdfIn PDF document text
    • http://kutscher-customs.de/gfx/userfiles/files/nosizupumatuze.pdfIn PDF document text
    • https://aluvioneschicamocha.sinecsas.com/ckfinder/userfiles/files/timinagipekogiwuzagog.pdfIn PDF document text
    • http://serextion2006.com/js/upload/files/75735126083.pdfIn PDF document text
    • https://bisnismedsos.com/userfiles/file/76765768596.pdfIn PDF document text
    • http://2015.letnifestiwal.pl/ckfinder/userfiles/files/zukuvanibu.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/6q0g1bsk0mkom9ur0qr5bural3/delineselagesuzudud.pdfIn PDF document text
    • http://veterina-hrib.cz/user-uploads/files/9146369594.pdfIn PDF document text
    • http://inkjetartandimage.com/Uploads/file/siwapunapuwuzugun.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16139c51e082fb---butuxuromebalewus.pdfIn PDF document text
    • http://stressmanagement-karriere.de/userfiles/file/65478062226.pdfIn PDF document text
    • http://matchedtubes.de/userfiles/file/57773622335.pdfIn PDF document text
    • http://ivankrivanek.com/userfiles/file/80639692699.pdfIn PDF document text
    • http://www.childofafrica.org/media/userfiles/file/xalotirure.pdfIn PDF document text
    • https://unique-u.biz/images/uploads/file/ninojomofawovepisagap.pdfIn PDF document text
    • https://scout-educationguide.com/userfiles/file/32351813961.pdfIn PDF document text
    • http://gekon.net/userfiles/file/tokedevifanoxal.pdfIn PDF document text
    • http://fotostudiovaccari.it/userfiles/files/24210025516.pdfIn PDF document text
    • http://www.portofmiamitunnel.com/system/js/back/ckfinder/userfiles/files/gotosojanak.pdfIn PDF document text
    • https://tumsad.org/img/editor/image/file/38640035074.pdfIn PDF document text
    • http://oxigensupplies.com/shipinc/userfiles/files/rexazulakixizukezojonimas.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613e4e0abdc6a---fukirewedemezejupib.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/1c4k8no03qioot3sf6a2gshl93/korozivukilogeg.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=games+to+play+online+without+flashPDF link annotation
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e615.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE615 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE27 19212 bytes
SHA-256: d7d384cd3bb2638d612b4493fc28bc017662c4ede971b8964d949d481188bfbb