Malicious PDF — malware analysis report

Static analysis result for SHA-256 411a39c385c859c5…

MALICIOUS

PDF

77.3 KB Created: 2021-07-08 22:57:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9dbaa691121df40dbcf966b16249443a SHA-1: 42c4455814c9468deb09b359eba612f98a5a1e32 SHA-256: 411a39c385c859c5411e0825fef8094f0d0a52936d91eac0deb12658c7bdba5e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was detected as a malicious PDF by ClamAV and an ML classifier. Heuristics indicate it functions as a link farm, hosting numerous PDF files on compromised WordPress sites. These links likely serve as lures for phishing or to distribute further malware. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa2528d8e2b---51820307782.pdf
    • https://chambredhotes-savoie.com/ckfinder/userfiles/files/lesuzoguxufarosal.pdf
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/leivho02mqfmbvf0vraett9u4n/nekezujujoxutiwapeluso.pdf
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c2c1f136fe1---98288316958.pdf
    • http://t-p-fortune.com/userfiles/file/wilamepufebafazej.pdf
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/9341tmetebi49vretm3hd5vpas/11279958836.pdf
    • http://ellenia3.eu/userfiles/files/25295338836.pdf
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/160d9399fba5fe---68207296383.pdf
    • https://coloreverything.love/wp-content/plugins/super-forms/uploads/php/files/4b2f33e4205d6156eb178ed7991ec424/13156199170.pdf
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608ff2fb67503---vutorakusubinagulaporep.pdf
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160742b7484b59---kavuxowukuvuxowo.pdf
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/p2mv3ge9n3n9cgo7n75902b6g7/samunad.pdf
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9834013435---siguvuxafawumamexepemudus.pdf
    • https://cornwallstaffagency.com/userfiles/file/26017823297.pdf
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/47d0bb90d8a220f79e8b5f7f86f3577c/teranajugagutesedubodeniv.pdf
    • http://accessiblevehicleservices.com/userfiles/file/17574799270.pdf
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160da9eea48cae---83851832254.pdf
    • https://klairtransport.com/uploads/files/30239970203.pdf
    • https://www.beadvised.co.uk/wp-content/plugins/super-forms/uploads/php/files/fefad46bc36b4c9a0c4420e8d039be6f/fuwefekab.pdf
    • http://iwishop.hu/file/ledujofuwa.pdf
    • http://fontanarosaserigrafia.it/userfiles/file/gifabogu.pdf
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606ceffe66780---57230180688.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=sodium+azide+thermal+decomposition
    • 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_off0000c422.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC422 16792 bytes
font_01_sfnt_off0000dc39.bin
e3f9340624550caee60bb4d407bfe01181ca092311d16be925d2c1ad48f22d57
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC39 11012 bytes
font_02_sfnt_off0000f5a4.bin
17fdb365d949fd09527840b514a6ba55be771d01d9b0258bc06af68d2a720207
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5A4 20016 bytes