Malicious PDF — malware analysis report

Static analysis result for SHA-256 5ace23fb35dab73f…

MALICIOUS

PDF

87.5 KB Created: 2021-09-18 23:31:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 7711a69ec2b1ead9f931078b3b242b63 SHA-1: 9a813382430197b68574529ac01cac4a3b1886cc SHA-256: 5ace23fb35dab73f9e7b1b6c8798ce4e138ec2807f8682f6454a2ce38272d54c
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ML classifiers and ClamAV, indicating a phishing or trojan distribution attempt. The PDF acts as a link farm, hosting numerous links to other PDF files, likely to obscure the ultimate malicious destination and evade initial detection. The heuristic 'SE_CALLBACK_LURE' suggests a potential callback phishing or tech-support scam pretext, aiming to trick users into interacting further.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://coretry.ru/uplcv?utm_term=langston+hughes+theme+for+english+b PDF link annotation
    • http://ruihuitax.com/files/file/danuvunabo.pdfIn PDF document text
    • http://jiehuist.com/userfiles/files/surebokudopomaxagesumi.pdfIn PDF document text
    • https://cjsc.se/ckfinder/userfiles/files/94592547927.pdfIn PDF document text
    • https://china-glass-mosaic.vegner.com/userfiles/files/20210913_051937.pdfIn PDF document text
    • http://iglozawiercie.pl/zdjecia/file/kokodedababosi.pdfIn PDF document text
    • http://galerie45.com/userfiles/file/tamepureranimizugigoturig.pdfIn PDF document text
    • https://avistravel.ro/userfiles/file/3196181154.pdfIn PDF document text
    • http://anm-av.de/uploads/files/24740460045.pdfIn PDF document text
    • http://gutachterbewertung.de/userfiles/file/puvopetuxixezewejanugud.pdfIn PDF document text
    • http://www.mousumibanerjee.com/fckimages/file/64465184726.pdfIn PDF document text
    • https://gastrotest.co/ckfinder/userfiles/files/33393587964.pdfIn PDF document text
    • http://huspanda.com/data/ckfinder/files/57277085420.pdfIn PDF document text
    • https://noddy.nu/images/file/biwipususino.pdfIn PDF document text
    • https://jhservice.net/imagenes/galeria/files/31274078674.pdfIn PDF document text
    • https://windfreeklima.com/upload/ckfinder/files/nenepujorekufezokobodov.pdfIn PDF document text
    • http://agama-rc.com/upload/files/1156696718.pdfIn PDF document text
    • http://www.madiran-cruduparadis.fr/ckfinder/userfiles/files/15849321982.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/973a0a0b7b80b7ed0ae36e6e56841d8b/rotowabibirajofukuli.pdfIn PDF document text
    • http://concilianavarra.com/userfiles/files/11156559375.pdfIn PDF document text
    • http://senvietsystem.com/ckeditor/upload/files/3752562455.pdfIn PDF document text
    • http://olech-rzeszow.pl/userfiles/file/milidodox.pdfIn PDF document text
    • http://signexpowholesale.com/project-new/christianbook/upload_images/file/simazunumulonisud.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/4154d78fa7085558c68db3c97c179883/75232852559.pdfIn PDF document text
    • https://tkbhanna.com/ckfinder/userfiles/files/84791426704.pdfIn PDF document text
    • http://brlairport.com/images/file/24926031677.pdfIn PDF document text
    • https://epgeptech.hu/ckfinder/userfiles/files/26123725822.pdfIn PDF document text
    • https://cakamuzejs.riga.lv/ckfinder/userfiles/files/44767021691.pdfIn PDF document text
    • 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_off0000f026.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF026 18384 bytes
SHA-256: d925ecbfb50f48c0eeecd42ece69f50e7e99b915869b298145c3547fcc3a7896
font_01_sfnt_off00011f2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F2D 10860 bytes
SHA-256: fba55f2c91cb7a0166c15cd71a112547cd67bc83171c2fc6bc9c09c92cbedf6a
font_02_sfnt_off00013809.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13809 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1