Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf6cde35718ebcdf…

MALICIOUS

PDF

89.9 KB Created: 2021-09-07 20:01:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4fb4185e0b3b7f0cd6254657b515f86c SHA-1: 0c310dcc3c9caf1a436891073c21d961532e9cb0 SHA-256: cf6cde35718ebcdf909df03846c850c8080b27e6adf74fa7eb3615adc130823b
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The file functions as a link farm, with numerous embedded URLs pointing to compromised WordPress upload directories and other disposable hosting. These links likely serve to redirect users to phishing sites or download further malicious payloads, consistent with a spearphishing attachment attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/160e4e74f06e18---vudepituvugo.pdf
    • http://gorisum.net/fckeditor/upload_file/file/rimukudigis.pdf
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/6d3c12c570587c743a29771f2acc5386/xigigulomugabuwirore.pdf
    • http://aliceinformaticasrl.com/user/pages/34376126037.pdf
    • https://bataretak.com/img/files/file/puvixisikajenivoxowiziwe.pdf
    • http://dansecyr.ca/pdf/file/43852609815.pdf
    • https://f27szerviz.hu/upload/files/vujofiwuwomaluvezir.pdf
    • http://learningkey.org/userfiles/46968143979.pdf
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160866c43089bd---41049241932.pdf
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16075cdd77177f---xuwapugu.pdf
    • http://myphamhelios.vn/luutru/files/leseta.pdf
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/e7b982b0fdca09740f39e4cad67edfc4/50251321122.pdf
    • http://otohondamientay.com/upload/files/15354334236.pdf
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a74270ed89e---zefuzomometijosabafo.pdf
    • https://rfcorporation.net/wp-content/plugins/super-forms/uploads/php/files/3d44aab2f1dc17943b51a33494578723/17209467803.pdf
    • https://globalclassic.org/wp-content/plugins/super-forms/uploads/php/files/9fdsljtmh3o889lvp5lo9dcohn/32382710845.pdf
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ee41fd0fb42---nisorusegadoxugaworoxumo.pdf
    • http://contelex.it/userfiles/files/xobotaluv.pdf
    • http://drivescuolaguida.it/userfiles/files/49822192529.pdf
    • http://syntra.pl/userfiles/file/74322870499.pdf
    • https://www.lucaslobker.com/minor/ckfinder/userfiles/files/8456070277.pdf
    • http://szentimresiklos.hu/upload/file/68213185722.pdf
    • http://ttlh.vn/storage/ckfinder/files/ruradisivifo.pdf
    • https://banghenails.com/upload/file/nodege.pdf
    • https://glowskincare.net/wp-content/plugins/super-forms/uploads/php/files/cc0dcc18296790dd2df9454bf13a3805/dixofopurudometo.pdf
    • http://zdrowejaja.com/Upload/file/30484356366.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=back+to+school+checklist+for+teachers+pdf
    • 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_off0000fa4e.bin
c4044fac3f1ac209440a16fb02099ae2db354d9e3651ab7a9624b6d0492631f5
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA4E 10756 bytes
font_01_sfnt_off0001133d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1133D 16792 bytes
font_02_sfnt_off00012b4f.bin
5b3f8f6673c862f56eacef88250698e8e777237fb8c5c0393fefba139c518be8
pdf-font-stream PDF embedded font (sfnt) at offset 0x12B4F 17816 bytes