Malicious PDF — malware analysis report

Static analysis result for SHA-256 af1b6d94f2511381…

MALICIOUS

PDF

84.7 KB Created: 2021-09-03 09:09:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 905622f81936f983cccda947917cb390 SHA-1: c1abf2c546d09c81cfd9a97b94be1f03d28da6ef SHA-256: af1b6d94f25113816945d86f78f4c9964d4a3a99c5ef092ad1aca4fffd2b96ea
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple domains, some of which are hosted on compromised WordPress sites or disposable hosting. The presence of numerous PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics confirms this behavior. The document body is heavily obfuscated and unreadable, suggesting an attempt to conceal its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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://jahanchart.ir/data/files/file/piselej.pdf In PDF document text
    • https://www.charityweiss.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606f9dbf2de28---8379279149.pdfIn PDF document text
    • https://codecs.ro/images/file/82541976235.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/20216261528282553.pdfIn PDF document text
    • http://wijnhuis-vaessen.nl/site/data/ws/files/sakuga.pdfIn PDF document text
    • https://www.bocamvigliesrooms.com/wp-content/plugins/super-forms/uploads/php/files/04c87dd8701d5207c16ef1c3ff327d19/kapakavodupugigimivora.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083b6d710567---21619892438.pdfIn PDF document text
    • http://tubemakingmachine.com/uploadfile/files/90355899227.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/1606d244972ac2---zovenu.pdfIn PDF document text
    • http://studiotecnicopinto.it/userfiles/files/tapulowusex.pdfIn PDF document text
    • http://kenzoum.org/home/integrity/public_html/ckfinder/userfiles/files/ranaririlovixijagib.pdfIn PDF document text
    • http://bukharageorgia.com/sites/default/files/file/rowedezexutizobefuv.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/4bvegods4f6fcf419src2b6tjj/93498275693.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072d60a0f57c---lojomexulir.pdfIn PDF document text
    • http://tablica-nieruchomosci.pl/uploades/fckeditorfile/zilurinidupuxezun.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16106383f5ec0e---34436214516.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b9285af134d---sakebofivewome.pdfIn PDF document text
    • http://iamsong.vn/uploads/files/womunivufemapijiwevimo.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160865f073fffa---8608679147.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607da8c439ba1---pedafijizejejubuzani.pdfIn PDF document text
    • http://thucphamchucnangmy.vn/uploads/files/poxawisowezafigu.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2cba1e14fb---lewetogat.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/98dbfecbea55b03e8b82707c6e9f2079/96585646894.pdfIn PDF document text
    • https://cuichi177.com/uploads/files/202108181112025877.pdfIn PDF document text
    • http://pensionpoint.cz/userfiles/files/13038135540.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=stainless+steel+main+door+design+catalogue+pdfPDF link annotation
    • 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_off0000df4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF4A 11136 bytes
SHA-256: 3e6ca66e18c3b51a7d3d57e08ef50dc57acab0a72292eaf63b398ba133bac129
font_01_sfnt_off0000f903.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF903 20324 bytes
SHA-256: b278557afc0d1bf91807f330fd308904e5c2f936fc10d4cbcaf959b5d9662a6e
font_02_sfnt_off00012cb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CB9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1