Malicious PDF — malware analysis report

Static analysis result for SHA-256 b257dee564c0402c…

MALICIOUS

PDF

84.2 KB Created: 2021-09-07 18:44:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 50422caebe906fe16b8e27a79a75aaf5 SHA-1: 943d2b63baef26b2d31864dfff739168ba4266f9 SHA-256: b257dee564c0402c26be4a1760750651e5ece3de3d8c75cf57ec5ac54f8906e7
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to potentially compromised WordPress sites and other unknown URLs, suggesting a phishing or malware distribution scheme. The PDF itself contains obfuscated content, but the presence of multiple external links and the overall detection profile strongly suggest it's part of a malicious campaign.

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://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/f2569f3fe4d6249f9c5603b2791f8f59/71265499715.pdf In PDF document text
    • http://stevis.cz/files/file/tabesuzililodozepu.pdfIn PDF document text
    • https://mimpishio1bet.com/contents//files/23950927900.pdfIn PDF document text
    • http://mastervin.ru/files/file/40577253445.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///lalobe.pdfIn PDF document text
    • https://birsamundapark.in/userfiles/files/jomej.pdfIn PDF document text
    • https://luminex.pl/upload/file/posudazevewomogomaja.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c9ad8db66de---resilovibakazemokiputinit.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608e8b00aac62---dewozekumutumosigo.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bda4ed94fc5---gomalatarevu.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a349cfa421f---79418886914.pdfIn PDF document text
    • http://studioghittigargnano.com/userfiles/files/wigezojafizapitigosuzo.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bd539d8ae9e---vazewolan.pdfIn PDF document text
    • https://sandzak.best/wp-content/plugins/super-forms/uploads/php/files/6be3d65b3379e672ae95c9ebe6698ea9/48147501353.pdfIn PDF document text
    • https://majubesar.info/contents/files/bobunad.pdfIn PDF document text
    • http://tillyardci.com/userfiles/file/ravodadavapanubi.pdfIn PDF document text
    • http://aclamerica.com/customers/CMS-IMAGES/file/94429604287.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/msuiob8v696hkua6ba9v7kgqgi/vuzojudadonarekuledosa.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acc1a398981---melulez.pdfIn PDF document text
    • https://www.bakirkoytemsilcisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607edbbd14ecb---xerosogafubepa.pdfIn PDF document text
    • http://www.huntsvillepr.com/files/files/71155788500.pdfIn PDF document text
    • https://indobaliart.com/sitefiles/file/xolizil.pdfIn PDF document text
    • http://spalovnachemolak.sk/userfiles/file/favaziba.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/gojusaz.pdfIn PDF document text
    • https://bselink.com/userfiles/file/44430003109.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=aadhar+card+application+form+download+pdf+kannadaPDF 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_off0000e540.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE540 10744 bytes
SHA-256: 09982dd16d36aaec99484de19b2cc9dce1837cc8c07693106c15ab4006945de4
font_01_sfnt_off0000fdc4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDC4 17372 bytes
SHA-256: 8291d39e3af3f12ed9f30272a805ab76461a755051530a553621e405faa3482b
font_02_sfnt_off00012a5f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A5F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1