Malicious PDF — malware analysis report

Static analysis result for SHA-256 73e37ab918813146…

MALICIOUS

PDF

69.5 KB Created: 2021-09-28 19:44:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 53ae6056f0500e22330848634293d652 SHA-1: ef1b7315c08218878eeae09eed6404a8d27c0581 SHA-256: 73e37ab918813146b50d01a0853914ffa9c9b1e265ca7f6b72e42aa9b761a6ea
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress upload storage, suggesting it's used to host or distribute malicious content. The presence of numerous unknown URLs further supports this, as they likely lead to the actual malicious payload or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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
  • 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.
  • 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://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1614f4f5ea3781---23494315103.pdf
    • http://www.gleason.com.au/application/third_party/ckfinder/userfiles/files/80677297090.pdf
    • http://lishasurgical.in/ckeditor/ckfinder/userfiles/files/19214511441.pdf
    • http://exim5.hu/_user/file/20714595061.pdf
    • http://hunicorn.hu/userfiles/file/taxotobedatuwer.pdf
    • https://pfollowers.com/ci/userfiles/files/65878390513.pdf
    • https://umiyawoodworks.com/fckdb/userfiles/file/gijevibozagu.pdf
    • https://namkhoasaigon.vn/web/images/files/49522665489.pdf
    • https://elegune.net/files/galeria/files/98168713793.pdf
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/16145ab2e98904---detidofivadazadebatu.pdf
    • http://rydelko.eu/userfiles/file/35191698506.pdf
    • https://netwindowvn.com/uploads/userfiles/file/29021756222.pdf
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/2f62f4ac397a01fda13913a3f616308c/94240465366.pdf
    • http://italianopizzeria-pg.com/uploads/files/jidodoretedo.pdf
    • http://alexandersorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sovowutubegoramajopuligeg.pdf
    • http://stark-tools.ru/images/uploaded/82292281217.pdf
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/7af81e8c746e0713626c7bfaeb50b76a/4252198482.pdf
    • https://rcvizovice.cz/ckfinder/userfiles/files/tukotitozisujenuligagovuw.pdf
    • http://nasledie-sluck.by/var/upload/file/fidubiw.pdf
    • https://psfund.org/public/uploads/files/cms_files/vuzego.pdf
    • https://dangeloremodeling.com/nbloom/fckuploads/file/kaxebizexita.pdf
    • https://subarini.ro/mm/file/girijubosodevanorulutep.pdf
    • http://objets.immoweiss.lu/userfiles/files/febepaladosofenuremuxe.pdf
    • https://kalyna.ua/sites/default/files/userfiles/file/28457018985.pdf
    • http://togul.org/sites/default/files/file/38215546513.pdf
    • https://laetitiabernard.fr/images/file/97130101412.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=the+colossus+rises+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b2b0.bin
2f2342b288d4997e69611e8a3dd98f5b167b7549dfe0690badea0e1c85c2e586
pdf-font-stream PDF embedded font (sfnt) at offset 0xB2B0 10416 bytes
font_01_sfnt_off0000ca5f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCA5F 16792 bytes
font_02_sfnt_off0000e271.bin
42129d62ece0bc7a91ae95df636812085065c832ea1b5d84e0b35ce7c32f2f46
pdf-font-stream PDF embedded font (sfnt) at offset 0xE271 15240 bytes