Malicious PDF — malware analysis report

Static analysis result for SHA-256 535ff3c44487cf45…

MALICIOUS

PDF

97.7 KB Created: 2021-06-25 20:12:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 8b602e48f4a96daab2f95e3a46a9bb7b SHA-1: 9b0497a0846238fdcae74df5dd26e7d60b561b1f SHA-256: 535ff3c44487cf45be47e347a42da274ef31beac0fa14203a752bdec9a868915
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and link farms, with several pointing to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL analysis suggest a malicious link farm designed to lure users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

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://wastran.ru/uplcv?utm_term=types+of+mechanism+ppt PDF link annotation
    • http://northcity.rs/slike/files/vuzuxixaxevowasudigegur.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5cdf5a895---82270911367.pdfIn PDF document text
    • http://mikailang.net/userfiles/file/20210607045041_974169787.pdfIn PDF document text
    • http://glotecgh.com/upload/editor/file/87734677844.pdfIn PDF document text
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/76586460530.pdfIn PDF document text
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cc8752d41e3---62329130714.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/2uoonetq85ha2m22mtoqfu55p4/ravedekikanefarujuvax.pdfIn PDF document text
    • http://seksdagen.nl/userfiles/file/fisedijosezijofi.pdfIn PDF document text
    • https://all-stage-meditation.tw/uploads/files/60c86bfceaedb.pdfIn PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/2f1606a12f3df60e04fe54d0de188e4d/97648122619.pdfIn PDF document text
    • http://cf-solutions.org/app/webroot/fckeditor/editor/filemanager/connectors/php/imgmedia/kakelilozob.pdfIn PDF document text
    • https://www.ideaklinikankara.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ce6abd6c97---zuwonab.pdfIn PDF document text
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/0a813f7b751b7719a29605c5b055496e/lakukonizejokudumu.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089a6f325368---wozuxokitiripo.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160c2c20a236be---kiritagatoziwiferekesi.pdfIn PDF document text
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4b48f2a8b9---potamidasigef.pdfIn PDF document text
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/00e434ddf1c71ad7a2ce1afb013a0a4f/tufiji.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab5b80712ed---rejifadekad.pdfIn PDF document text
    • https://popa.com.br/wp-content/plugins/super-forms/uploads/php/files/997a86484a474239101ac78b8ccf0600/buguxiwelimejitupu.pdfIn PDF document text
    • http://lighthouseofworship.com/clients/44803/File/87918720354.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/sr0un9qiffmv1ue8tb79v3u782/rejidalobotiloxalizogenu.pdfIn PDF document text
    • http://agnieszkapawlik.com/userfiles/file/luzibinezaribalum.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/12822605445.pdfIn PDF document text
    • http://arunimaflavours.com/userfiles/file/5911048110.pdfIn PDF document text
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/430635e21f14b8138111df67191968b0/25567840808.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_off0001156a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1156A 10676 bytes
SHA-256: 73639844e98f9d488d3db9855478580929882a14313480f7071b241f66a8d777
font_01_sfnt_off00012dca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DCA 21564 bytes
SHA-256: 1e0f474e0736d5eade5568a8e70c21466958bf5a9187cc15bd138774de951612
font_02_sfnt_off000161a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x161A7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1