Malicious PDF — malware analysis report

Static analysis result for SHA-256 35909a41711ba76c…

MALICIOUS

PDF

93.6 KB Created: 2021-08-11 15:50:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 9ed61de9ce2112ffa5bd1176d721e714 SHA-1: c75b63cdfcc89bc9f52272c8340353f660bdf241 SHA-256: 35909a41711ba76c6af815b8bdea3d45fd900166ebc79b379af45e9a0d3e562e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file identified as malicious by ML classifiers and ClamAV. It contains a link farm pointing to compromised WordPress sites, which in turn host other PDF files. The presence of multiple PDF files hosted on compromised CMS upload directories suggests a coordinated effort to distribute malicious content. While no scripts were explicitly extracted, the nature of the link farm and the detection as a phishing trojan indicates an intent to lure users into downloading and opening further malicious documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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 http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160a37ebb56fb9---nokudarezazajikubul.pdf In PDF document text
    • http://mdsalon.ru/img/lib/file/3944061259.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/u831qg73qv8ul9dqcvmcud40lm/goluxesutivogu.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160d3a6ddb9ee5---nofoguxakulewukutave.pdfIn PDF document text
    • https://dudikom.pl/userfiles/file/48377525876.pdfIn PDF document text
    • http://perfectionistpaintingnj.com/ckfinder/userfiles/files/xipemogu.pdfIn PDF document text
    • https://badoza.net/userfiles/file/36820913005.pdfIn PDF document text
    • https://reparation-mobile.net/userfiles/file/nudifefolelikidizo.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160f567d0ae918---pusotowodo.pdfIn PDF document text
    • https://xuanhongkhang.com/upload/files/vawobapiguwinerek.pdfIn PDF document text
    • http://www.taylormadetc.com/siteadmin/ckfinder/userfiles/files/32994736450.pdfIn PDF document text
    • http://stavclearing.ru/upload/files/jifijuxibivejedevan.pdfIn PDF document text
    • https://medtek.vn/storage/file/21161838919.pdfIn PDF document text
    • https://elitestrategyglobal.com/wp-content/plugins/super-forms/uploads/php/files/5eda02762f2449e461cd04370def6b26/taxinibov.pdfIn PDF document text
    • https://ms02bet.com/contents//files/85947865074.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/773dd95e72a8f9f8d633762b96f98880/70927825770.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/16070269c7a046---kosivufezadojurate.pdfIn PDF document text
    • http://koryosushi.com/uploads/files/vitesikub.pdfIn PDF document text
    • https://moto-trend.cz/public/files/fck/file/bazobapodoriponaduji.pdfIn PDF document text
    • http://vinmexindia.com/uploads/86613503218.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e5a6357df4---79114594771.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4b257dcfdc---51548030282.pdfIn PDF document text
    • http://pvhs1980reunion.com/clients/e/e5/e5e9f74eb83211af097e98bf68d59c4c/File/damijezojeto.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609833a05ea0b---watobeketazumiwadalil.pdfIn PDF document text
    • https://www.ideaklinikankara.com/wp-content/plugins/formcraft/file-upload/server/content/files/160738b7acb11b---lekad.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=one+piece+manga+chapter+1001+spoilers+redditPDF 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_off0001062b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1062B 18768 bytes
SHA-256: 3f127a9bef79b9e277e586c2ec3b92da49dcb212d29f63fc594bfe46a31ff1ff
font_01_sfnt_off0001353b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1353B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014d52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D52 11160 bytes
SHA-256: 38233576ed084f16cdc2913be59807da4840170aa8aae82f651963123e294bf4