Malicious PDF — malware analysis report

Static analysis result for SHA-256 a632bc65f8f53e8d…

MALICIOUS

PDF

81.7 KB Created: 2021-09-22 15:28:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 01098bb3b627b404acbaaf1ad8b24fc1 SHA-1: d61bc3bcbdb598b37e2bebfda61f7c2aa3f33d6e SHA-256: a632bc65f8f53e8dcc71147555260f173db7564a01cb5e49bd98bd25a30ba0ad
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to disposable hosting or compromised CMS uploads, characteristic of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The document body is unreadable, but the heuristics and numerous URLs suggest a malicious redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://cokhivietuc.com/img-vietuc/files/62912289878.pdf
    • https://e-fasteners.eu/media/file/48458322776.pdf
    • https://strategie-forex.com/ckfinder/userfiles/files/tetusasoparokawedefuwesug.pdf
    • https://mar3ol.com/Files/files/molik.pdf
    • https://bishopsalamatkhokhar.org/userfiles/file/lagixukitewuvujutujifozaz.pdf
    • http://sky1981.com/asset/uploads/files/54587618642.pdf
    • http://handgun.ee/media/file/kimemelupodinusotujujefi.pdf
    • http://tcsklife.com/filespath/files/20210913210710.pdf
    • http://maynenkhiinverter.com/media/ftp/file/wanux.pdf
    • http://www.hgbehringer.de/img/files/files/jumixalafemudilifiwuvo.pdf
    • http://syarmarka.ru/userfiles/files/wopivozusedipu.pdf
    • http://chanakyaaerospacedefence.com/userfiles/file/37915290491.pdf
    • http://qualityfirstservices.pro/testingsites/advantage_aviation/assets/media/file/52961338968.pdf
    • http://uceng.net/_UploadFile/Images/file/39094325093.pdf
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16132fc3e4314f---25027318738.pdf
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144602f1570e---99816852528.pdf
    • http://electrogalicia.com/electrogalicia/recursos/archivos/dipugegojulukudefivibapag.pdf
    • http://www.childofafrica.org/media/userfiles/file/22377554490.pdf
    • http://polyalpan.hu/_user/file/23254939803.pdf
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e01da2e0dd---11372242268.pdf
    • https://wrd13.com/force/file/48348376723.pdf
    • http://domingo.hu/ckfinder/userfiles/files/21610618636.pdf
    • https://dmitrovka-zn.ru/admin/ckfinder/userfiles/files/sogizim.pdf
    • https://vantainoidia.vn/ci/userfiles/files/terasebanumejarazuw.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=unused+free+robux+codes
    • 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://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_off0000dc3e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC3E 16792 bytes
font_01_sfnt_off0000f455.bin
0905f8ea8cf8743cef38f39bc33fdb3ddf22dce40288d4ea9fc71895662854a4
pdf-font-stream PDF embedded font (sfnt) at offset 0xF455 10420 bytes
font_02_sfnt_off00010c0f.bin
f9d43ccf762e36952383a28494256b6b7e96b66dd165afdd5d2b126e24dce3ab
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C0F 18176 bytes