Malicious PDF — malware analysis report

Static analysis result for SHA-256 77def6a4c7af7ac3…

MALICIOUS

PDF

80.6 KB Created: 2021-06-18 03:11:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 2fe8a36e2c331725b2f71390ca8709aa SHA-1: b6a0ce22076cb69d35b5df90d68d8bed6fcb1219 SHA-256: 77def6a4c7af7ac3299a1ec33685de43b459a26d229a1f3d914ad9fdb91862f5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress sites and potentially malicious domains. The embedded URLs and the nature of the heuristics suggest the document is designed to lead users to phishing sites or to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://synerhu.ru/uplcv?utm_term=kingdom+of+ash+and+briars PDF link annotation
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/d8d515b4c94179801ad33c634d8aa065/98759296590.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16071996ecb38d---timow.pdfIn PDF document text
    • https://carea2plus.com/wp-content/plugins/super-forms/uploads/php/files/778180ea8f2a9422efc61a258a37335a/16240673075.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/6ed6c3f44575e12b464894d336deb695/votevuti.pdfIn PDF document text
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/5d92bfc52f827366856a9171218f07f5/46740366049.pdfIn PDF document text
    • https://pensiuneavalentina.ro/app/webroot/file/numororituvepizixosoxow.pdfIn PDF document text
    • https://nnkcreations.com/userfiles/file/tasoxagojij.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/at2j9c9gr6c73bcobcipgm9fl5/19129120951.pdfIn PDF document text
    • http://jcon-aps.dk/userfiles/file/54445465887.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607e5f76e97fc---wilaxekerewuvogojuna.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a077160bc21---gedorusadoner.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/hcquaf1ftaiva9il1mq0nklmc5/mapubomokomezegamik.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/fefa17f1c678d88e14899a6c44e0d218/73363763099.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160835025e55e7---jajedijiwesosuno.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn 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_off0000e867.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE867 5396 bytes
SHA-256: 93941e03cf52d8ff8427b9f239c1da5c73068ba313d5128471647d74e547315c
font_01_sfnt_off0000fa9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA9B 11148 bytes
SHA-256: 42290baff161bbc12870e35443dbda0b26279919933740bdb89be66e3a8b7ebd
font_02_sfnt_off000120be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120BE 16092 bytes
SHA-256: c9557d91917e40dbb2ce09b7ef560a04a9a832ffe2ebcac6b50408a58351272e