Malicious PDF — malware analysis report

Static analysis result for SHA-256 27c811a965ac6bd6…

MALICIOUS

PDF

85.3 KB Created: 2021-08-29 04:51:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: eec2c4652c09c5558141e0742b0b5385 SHA-1: e002f721d21cb8842ddc5ce6516603f8c888facb SHA-256: 27c811a965ac6bd61812c39db29df3e7c4775504061f9b100b7ed2c598dc68b4
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress upload directories and other disposable hosting, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. The presence of multiple PDF files hosted on compromised CMS uploads reinforces the malicious nature of this document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://mfdesign.hu/files/file/xerutenegulexesaje.pdf
    • http://amoy-art.com/Upload/file/deravezi.pdf
    • https://www.asahinadigital.com/wp-content/plugins/super-forms/uploads/php/files/6p0qcse6fp1mqrhqk9tls6pdlq/94138033176.pdf
    • https://goldenapp.net/file/jadadirikokoferofo.pdf
    • http://resumesfromabove.com/userfiles/file/sozomogibotumokoxokerin.pdf
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160be1893090af---litowemujizanazumo.pdf
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c1f8e19795---rokulikujurimopita.pdf
    • http://insk.ru/img/userfiles/file/95114821135.pdf
    • http://dellalontra.it/userfiles/files/57765898366.pdf
    • http://0-50.ru/userfiles/file/vuvipipuratipabipute.pdf
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070fea9e199d---kobega.pdf
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/fe586abc08c7e28ad4940c351d1710dd/77817490478.pdf
    • http://stjconsulting.it/userfiles/files/75333407764.pdf
    • http://global-insurance-broker.de/downloads/20919921396.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e6e2aa3157---61823777578.pdf
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1c33c01dd7---31787907741.pdf
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/b6b5306b54a0a5946f62604d73463dd1/kivamewexajuxozojifozaliz.pdf
    • https://schilderlesvakantie.nl/ckfinder/userfiles/files/dinukunadegafopetuj.pdf
    • http://tranindo.com/Uploads/userfiles/files/gopimuzo.pdf
    • https://istanajpdua.com/contents//files/39374110015.pdf
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b6662150285---67506697700.pdf
    • http://dezis.ru/uploads/files/20265201911.pdf
    • https://apoiotelecom.com/imagens/img_fckeditor/file/82677471635.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c955644fefd---12564034518.pdf
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4708606953---zosutud.pdf
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1608b312a3fe2e---59549506643.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=the+study+of+knowledge
    • 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_off0000e3b4.bin
a4bc12e7723aa98bb853d56c61fdb26a0970ab47bd734fbad0edd5b6dcf7a49b
pdf-font-stream PDF embedded font (sfnt) at offset 0xE3B4 19584 bytes
font_01_sfnt_off000115d2.bin
4bedfb8e2f7ffc4a491b1a9a1d34fac3ef680ee9593bbe4a31b599728701517f
pdf-font-stream PDF embedded font (sfnt) at offset 0x115D2 10632 bytes
font_02_sfnt_off00012e09.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E09 16792 bytes