Malicious PDF — malware analysis report

Static analysis result for SHA-256 b82c106848572d89…

MALICIOUS

PDF

79.8 KB Created: 2021-09-21 20:03:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0af0fd18a641a38f13125151f4cf742d SHA-1: 771219ea1d26e783095680ef5b304c4754acc13c SHA-256: b82c106848572d89d1225848d539d3dc74b4b8d1882387bfe7cc1bc587c1302b
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 ML classifiers, indicating a high likelihood of malicious intent. The PDF contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, suggesting it functions as a link farm. These links likely lead to phishing pages or malware downloads, aligning with the 'Pdf.Phishing.Trojan' detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://synerhu.ru/uplcv?utm_term=firechat+apk+download PDF link annotation
    • https://urology-andrology.com/userfiles/file/medixewakanusisonuzegetas.pdfIn PDF document text
    • http://energyexcess.com/userfiles/file/86703092471.pdfIn PDF document text
    • http://jutaek.humenia.com/upload/userfiles/2021/09/files/210917230500.pdfIn PDF document text
    • http://hondaototanan.com/upload/files/jugule.pdfIn PDF document text
    • http://bualuang101.com/backoffice/upload/files/41851997679.pdfIn PDF document text
    • http://www.thaiboat.net/image/upload/File/51911886768.pdfIn PDF document text
    • http://palmdale.thepokeluau.com/uploads/files/54463842538.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/loiv9qrneh8h64em2pomrb48jj/30722164189.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-9-5/20210905065234343619.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614902574cd22---22829806084.pdfIn PDF document text
    • http://fujiya-burbank.com/uploads/files/13875637798.pdfIn PDF document text
    • http://dgjinhak.kr/DATA/upload/files/202109060252502334.pdfIn PDF document text
    • http://all-paca.com/ckeditor/ckfinder/core/connector/php/uploads/files/fuzulafebef.pdfIn PDF document text
    • http://e-park.es/img/uploads/files/23449066535.pdfIn PDF document text
    • https://www.la-melodie-des-saveurs.fr/ckfinder/userfiles/files/36046717993.pdfIn PDF document text
    • https://acrgruppe.de/userfiles/file/40411506838.pdfIn PDF document text
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/5d2e1f150e9cc14333fa70f90e188c57/13747822363.pdfIn PDF document text
    • https://www.agencesramos.com/ckfinder/userfiles/files/3709243271.pdfIn PDF document text
    • http://av-jet.ru/userfiles/file/feripogubulidos.pdfIn PDF document text
    • https://studioconcept-stand.com/fck_userfiles/file/87793277475.pdfIn PDF document text
    • https://cyc-catering.pe/disac/userfiles/file/20459400567.pdfIn PDF document text
    • http://himalayakebab.irafbrothers.com/shipinc/userfiles/files/bogufesivuxariwelutego.pdfIn PDF document text
    • http://star-transform-moscow.ru/uimg/files/jikelojulaxibo.pdfIn PDF document text
    • http://benthanhsgfarm.net/images/uploads/files/ruzexogazefeduwebubazov.pdfIn PDF document text
    • https://dehaventransportation.com/home/de/public_html/ckfinder/userfiles/files/kisujinogugokik.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_off0000d30e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD30E 17764 bytes
SHA-256: 32994cabe44245549d6b1ba7395e5cd459a28a68216bbe2b44cebcea73b63947
font_01_sfnt_off00010144.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10144 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001195b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1195B 10596 bytes
SHA-256: 147d00acc7ac20b82009f370a9f72b7c1f703c45fe6d8fb7a2c8b54f78e3be02