Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c31a54880d8e573…

MALICIOUS

PDF

87.9 KB Created: 2021-08-08 11:32:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ccabf00160efbf159d4f8e30ffba43a5 SHA-1: af1840d00826d3edc183b3731a7e09c342c4863a SHA-256: 4c31a54880d8e5738fe0109d3a6ec7b76a19086703c57c4b1415660de65a3bb0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of external URI heuristics and link farm indicators supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://ketchas.ru/uplcv?utm_term=stalker+shadow+of+chernobyl+trainer+download
    • https://multimetrics.com/ckfinder/userfiles/files/39306357287.pdf
    • http://xn--clinicaquirogavilario-vbc.com/wp-content/plugins/super-forms/uploads/php/files/7uo8ebptqnv2trr497cjfmgg85/pasome.pdf
    • http://kamerton.nl/clientfiles/66163363769.pdf
    • https://gregor-biffiger.ch/userfiles/file/fanesotirodipon.pdf
    • https://aartipalette.com/userfiles/file/diwizukudopedelugatu.pdf
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/otfflea78d8r8mi396u1ne8cfn/mekewenobosizijobupereb.pdf
    • http://hosungtour.com/FileData/ckfinder/files/20210712_14D9542970B8DC39.pdf
    • http://czechdidgeridoo.com/admin/upload/file/36419613698.pdf
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/4gpanke7phop4t68nj94cpg3ka/zefanupilusonel.pdf
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/c07c15ccb5bb3b61a32d4e9c3bbb55ad/52685290343.pdf
    • https://akproauto.net/nbloom/fckuploads/file/21011179949.pdf
    • http://ridendo.cz/files/file/vaxabimavuvifojikegivaga.pdf
    • http://lblussana.it/images/file/ludano.pdf
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089fee694f78---85367060815.pdf
    • http://briarcliff68.com/clients/71184/File/98879622458.pdf
    • http://bochosushi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e5bba88fbe---96727015350.pdf
    • https://www.duffylighting.com/wp-content/plugins/super-forms/uploads/php/files/fd9fd0a1f221db28f7335eedf48aa395/miletaduruwimabexedinenad.pdf
    • http://reszke.pl/fckeditor/editor/filemanager/connectors/php/file/88162324163.pdf
    • https://eatorhours.org/e-bussiness/fckimages/file/rotexawusamarakib.pdf
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160d3aadb3b697---53888874672.pdf
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/11arpdmiv1a3k3dvq6f87lk9ja/wosilebib.pdf
    • http://kochamsushi.pl/UserFiles/file/rabafajutodobixidojokugud.pdf
    • http://namngonviet.vn/user-/files/tadedexanutaj.pdf
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/vunvhfdajpvs4uuj0vbt687ro0/ximex.pdf
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087e35d44a4b---fudofujafotuwaferovekug.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_off0000f174.bin
34a3d55e27c00e199877f582d83e9575da68f992b50057445ecee96841d38691
pdf-font-stream PDF embedded font (sfnt) at offset 0xF174 11080 bytes
font_01_sfnt_off00010b49.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B49 16792 bytes
font_02_sfnt_off0001235b.bin
090c4eedb2e08f37b747762d31c5fe7bd0d2783ca79ed62f3ca9daf533545d0c
pdf-font-stream PDF embedded font (sfnt) at offset 0x1235B 17480 bytes