Malicious PDF — malware analysis report

Static analysis result for SHA-256 861545bc61a386ee…

MALICIOUS

PDF

124.8 KB Created: 2021-06-08 03:41:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 1fc83c88cda64e8d08c263c56ba1984a SHA-1: 8c236b76b42bfa62dca444e48bd20274c5c5628c SHA-256: 861545bc61a386ee2e6437af36c68e40b60c13e8465a4cf6bf08c75af3d67b21
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains multiple links to external websites, many of which are hosted on compromised CMS platforms or disposable hosting, suggesting a link farm designed to redirect users. One prominent URL, 'https://nomylo.ru/uplcv?utm_term=instagram+blue+tick+mod+apk', indicates a lure for a modified application. The ML classifier and ClamAV detection strongly support the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://nomylo.ru/uplcv?utm_term=instagram+blue+tick+mod+apk PDF link annotation
    • http://www.kickcommerce.com/userfiles/file/zutifuzinoj.pdfIn PDF document text
    • http://plenaadoracao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607bec7d85301---81378977877.pdfIn PDF document text
    • http://reelproductionshd.com/userfiles/file/gijusotoxawes.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/6376545b93296eb998219488af5aa57c/92305179982.pdfIn PDF document text
    • http://boathousebrokerage.com/userfiles/file/dofevanatotu.pdfIn PDF document text
    • http://kingalbertltd.com/uploadedfiles/file/zosakotetamarogezulipakej.pdfIn PDF document text
    • http://nfc.soo.jp/file/82294626360.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/ellujslv53hv00aojpcakee3d7/31943096734.pdfIn PDF document text
    • http://ajtoablakcentrum.com/_user/file/xuwomon.pdfIn PDF document text
    • https://www.engltg.com/wp-content/plugins/super-forms/uploads/php/files/6c8908df63ac43b3aecb69aef6bcd648/9168031952.pdfIn PDF document text
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/61ce5225b9e52be46300d1a163c1feff/jajomumivemomevujebepeded.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1609db0dfdfea1---pumeridus.pdfIn PDF document text
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608acf4048e00---48697552044.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160b19c050480e---42485624448.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00017935.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17935 5532 bytes
SHA-256: e3db6f964081e0d2c0a218058d6467da5073817732fecd6690ee6d32eda09dd3
font_01_sfnt_off00018be8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18BE8 2284 bytes
SHA-256: 42ed5c7cd0abfdf26d7c2fe7473f3bb585fa19eb630dae685e34e1e871d58a69
font_02_sfnt_off0001963f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1963F 17912 bytes
SHA-256: 4d304d4a8143647a9cc7e2b9502faa8aa3dceecbd07102904a8cb18156c8e8ed
font_03_sfnt_off0001cad1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1CAD1 17424 bytes
SHA-256: 2e66e2ebbe6834be1c6444a2d25c6f33bcbdeb6904df625515c042dc88dd0207