Malicious PDF — malware analysis report

Static analysis result for SHA-256 6782c21b5027e1c6…

MALICIOUS

PDF

85.1 KB Created: 2021-09-06 09:59:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 9b7b56c976b285a03e3cc21562b42cb4 SHA-1: 35e3a1393b9828a40f46c444c901b3f26d4077c5 SHA-256: 6782c21b5027e1c6a6ab8b569721483ab8b9405074dfa3faf45e8fd2d9228f2e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. While no scripts were explicitly extracted, the nature of the URLs and the heuristic firings point towards a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://synerhu.ru/uplcv?utm_term=bangla+cv+writing+pdf PDF link annotation
    • http://jtour.vn/userfiles/file/ledeke.pdfIn PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/e2b5a581e184a48804c8670b94e9332e/vubanimafivo.pdfIn PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/dca99635383565c56622197607cdbc38/jovobagatelubigivu.pdfIn PDF document text
    • http://arunimaflavours.com/userfiles/file/89707738825.pdfIn PDF document text
    • https://thuaphatlaihoanghuy.com/uploads/files/sazesoxo.pdfIn PDF document text
    • http://thetachikappasigmaalumni.org/clients/5/56/56ac51e2ee760b54d3ff8b7d53c877b7/File/21786371746.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160de0f610cfc7---nogeresujewex.pdfIn PDF document text
    • http://tavaszitura.eu/userfiles/files/rewimuzuxitojajigawo.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/0bdrun84j9knlci5u6a50d4bvk/66013410189.pdfIn PDF document text
    • http://dogable.de/userfiles/file/26192404996.pdfIn PDF document text
    • https://thetitangroup.ca/wp-content/plugins/super-forms/uploads/php/files/fd178651b9ba6561bd41b74ed2a0f457/59037557102.pdfIn PDF document text
    • http://wahiclassof69.com/clients/874294/File/15226266885.pdfIn PDF document text
    • http://phdpecs.hu/userfiles/files/vizefetubusuxi.pdfIn PDF document text
    • https://atl-50.com/files/file/69631077299.pdfIn PDF document text
    • http://metamorfoza-krosno.pl/userfiles/file/pedudiburi.pdfIn PDF document text
    • http://ristorantebiscione.com/userfiles/files/zapizujejubabido.pdfIn PDF document text
    • http://proxima-design.cz/files/file/nigefadonerufat.pdfIn PDF document text
    • http://halanmilk.com/upload/files/36758050836.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095b08ea79d3---16732927418.pdfIn 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://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_off0000e5e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5E3 19172 bytes
SHA-256: 8b73ab4bd460297ba1c8a06ddec708eb43c5dc4b945120b4c7504e75f4716c36
font_01_sfnt_off00011747.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11747 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012f5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F5E 10580 bytes
SHA-256: fca8b39d72fe2ac3cdbe6df6829384ebe7a58a212a198c9bcab07bdb4cc9c616