Malicious PDF — malware analysis report

Static analysis result for SHA-256 37f1981c8369656d…

MALICIOUS

PDF

142.7 KB Created: 2021-08-26 05:44:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 3939f663600db4b9b424be9bac1711fb SHA-1: c869b1b5a0d434fa10f7571e6686fdfa34c42e6a SHA-256: 37f1981c8369656d04bfadd85c6f2c4afc4684d9ce8baff599ad98625ea2a988
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous other PDF files hosted on compromised websites, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to distribute further malware or phishing content. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

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://sapaelitehotel.com/webroot/img/files/23400169607.pdf In PDF document text
    • http://jdjfjx.com/images/upload/File/34887928961.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/3e3a6c511ad55a67237b29e403210560/vasuzef.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160886abe2e69d---kajemofokaribij.pdfIn PDF document text
    • http://kunjipsc.com/uploads/files/tujosewu.pdfIn PDF document text
    • https://heuresromantiques.com/upload/files/32812361199.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608235d447895---zewutalatesevoruvukadapo.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/3850ac91f66f0b2fd14603ac8da18bbe/62357090952.pdfIn PDF document text
    • http://erex.hu/upload/file/68618858935.pdfIn PDF document text
    • http://musorcentrum.hu/files/article/file/dulabuvarul.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/1844287015.pdfIn PDF document text
    • https://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/e99afcc64974748a82fb03f4d13df47e/sodipixokumesofamuse.pdfIn PDF document text
    • http://chinocorporatechallenge.com/clients/6216/File/wibefebifixum.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609194a9ad5aa---sejobo.pdfIn PDF document text
    • https://rittenhousesmiles.com/wp-content/plugins/super-forms/uploads/php/files/157b15254e6f50e9c62b7a878286bdba/guzisizumukuwa.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608690557ad57---sifuvinen.pdfIn PDF document text
    • https://denimder.org/resimler/files/worinowurarofopigimof.pdfIn PDF document text
    • https://icon-studios.com/userfiles/file/gufozutokoto.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607f2fc82fba1---23535309376.pdfIn PDF document text
    • http://thegibbsfamilyreunion.com/clients/d/d9/d929505c7faf6263097cc97620c39d65/File/pegokeradipujevufevexabi.pdfIn PDF document text
    • http://sns.hu/_user/file/60049546762.pdfIn PDF document text
    • https://www.nexidia.it/wp-content/plugins/super-forms/uploads/php/files/bed03ec47ffce3e5f04fd68185311f93/rebidiroremuv.pdfIn PDF document text
    • http://kargo-box.com/uploads/files/nofimakor.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=st80+iron+roughneck+manualPDF 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_off0001c9b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C9B3 18644 bytes
SHA-256: 6503744fc8460251fd2f4e07a8961e9c8e27fcc89cb277f23d401bf48c8766aa
font_01_sfnt_off0001fb01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1FB01 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00021318.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x21318 11104 bytes
SHA-256: 4a5e2ee93fa8fca5e6d02a88cc715e36deaa7c3842b6691a1482263613a505c3

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