Malicious PDF — malware analysis report

Static analysis result for SHA-256 51df3f4ba70d002b…

MALICIOUS

PDF

86.2 KB Created: 2021-07-30 09:19:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0783a351bfb213770f15dc21b626c780 SHA-1: 567bd2e70445f7fc7939a1f471a2afbae0228c50 SHA-256: 51df3f4ba70d002b88c934b5b8f93f0631459582e16a738c3600901e96c68db5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV detecting it as Pdf.Phishing.Trojan. The numerous external URLs embedded within the document, many pointing to compromised WordPress sites or disposable hosting, suggest a link farm designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this. No scripts were extracted, but the overall structure and URL patterns indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://crewmak.ru/uplcv?utm_term=ap+human+geography+chapter+2+multiple+choice+test
    • http://www.niziointerior.pl/upload/file/zatuzumo.pdf
    • http://bsp-plovdiv.org/ckfinder/userfiles/files/xuzulonaxe.pdf
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e77c4bf3c4c---kuniroperedejasaji.pdf
    • https://law.com.sg/wp-content/plugins/super-forms/uploads/php/files/d73651e95d257c342ba131217cc37b68/24483331002.pdf
    • https://www.dolphinrfid.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b564c68d4e9---83505335977.pdf
    • http://twfindia.in/userfiles/files/74739385421.pdf
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/399a625c0d047ecb026572faa8ea2da4/xamarubagizerolinufo.pdf
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/d4d55e9c8ac62788f1ec4121c9b01a56/70176338930.pdf
    • http://healhumanity.foundation/userfiles/file/jatonujilo.pdf
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1607b1988280d9---44734382693.pdf
    • http://loveperfectionschool.com/upload/file/96941649652.pdf
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae6eab5e504---31728535762.pdf
    • http://arcdesantmarti.com/biocop/Images/images-editor/file/46430065269.pdf
    • https://lawpropertyconsultants.co.uk/wp-content/plugins/super-forms/uploads/php/files/boqpqcq4g7okqcoj9u8v5ro1mo/15844871258.pdf
    • http://accessiblevehicleservices.com/userfiles/file/liregefafitip.pdf
    • http://ibiforstarlight.org/clients/3/3c/3cfcca4e360ca8807b7dd7d6e7cbeae0/File/355849755.pdf
    • https://shared401k.com/wp-content/plugins/super-forms/uploads/php/files/d29251368daad01f28a1c0946d1984a5/reroxowagakogoxekumobajuk.pdf
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1609c67e624732---86942629780.pdf
    • http://dobrasekacka.cz/userfiles/file/fumilobewiz.pdf
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/1259e65396a2ea243c6bb96a8fd20c30/48638838672.pdf
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb9ae4324a---ridorawebunege.pdf
    • http://nguoigiupviec99.com/webroot/img/files/roxipetise.pdf
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/a0861a714e5646bedf7411c3f0fa22f4/mapofelejerefaxasejom.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e995.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE995 16792 bytes
font_01_sfnt_off000101a7.bin
4232434081aa24a0b957067c098305cf129ac0919e32fd9d980df5e1e5b4f86a
pdf-font-stream PDF embedded font (sfnt) at offset 0x101A7 17512 bytes
font_02_sfnt_off00012f7b.bin
2adf66f8baeac858c8fa91bc0d7b337a8765dd96430196b58d9b166b38b482da
pdf-font-stream PDF embedded font (sfnt) at offset 0x12F7B 11136 bytes