Malicious PDF — malware analysis report

Static analysis result for SHA-256 591bea932df49312…

MALICIOUS

PDF

80.0 KB Created: 2021-09-07 08:59:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 187afc0d7a5f50fb2b148ee6a8ffab1c SHA-1: cb6c0cd081dfbcf3d6bf49178a9112f13a943b5d SHA-256: 591bea932df493127300b4676dd169c38e3cbdd28812579ec3315e06ae28ceed
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/54a1e1c84d8cb9b41eaa8f10481ab78c/14387110702.pdf In PDF document text
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a519e58a56b---razetebebale.pdfIn PDF document text
    • https://cruiseship.cruises/wp-content/plugins/super-forms/uploads/php/files/gi76qa37dh522oe85rq2c4un0s/tuvuxedotaraz.pdfIn PDF document text
    • http://tianlanip.com/filespath/files/20210830133833.pdfIn PDF document text
    • http://kortennis.co.kr/B/ck/ckfinder/userfiles/files/poluzeguvan.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a5d9832f71e---71275528485.pdfIn PDF document text
    • http://jiuxingchaoshi.com/uploads/file/010638153074.pdfIn PDF document text
    • http://sns.hu/_user/file/20982725431.pdfIn PDF document text
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608bad946b74f---wolijugagiminuko.pdfIn PDF document text
    • https://www.conkite.com/wp-content/plugins/super-forms/uploads/php/files/ba74d94efde999685ebd1b4165cd173d/7453478218.pdfIn PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a1dedae958---86237838379.pdfIn PDF document text
    • http://schroniskoorzechowce.pl/ckfinder/userfiles/files/xazamofuvilenurepadifuwib.pdfIn PDF document text
    • http://austria-ex.com/images/blog//file/67554682704.pdfIn PDF document text
    • http://consade.com/userfiles/file/89785573183.pdfIn PDF document text
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/3hk66ssv97750duv1su9mr3v33/bisosabimokusinefegezol.pdfIn PDF document text
    • http://jakpaisanestate.com/images/upload/files/21158918562.pdfIn PDF document text
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160bbb91bc0b14---63372568679.pdfIn PDF document text
    • https://bomnuocebara.com/quangbasanpham/app/webroot/upload/image/files/92315026201.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=definiciones+iso+9001+pdfPDF 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_off0000d39a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD39A 17648 bytes
SHA-256: 35237b16116040f2fdc23ee9b59263adc62b2f60a4be8f251568005d7444efe6
font_01_sfnt_off0001012d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1012D 10548 bytes
SHA-256: a960c411f99e21cfede5844c063225ceb1f97c0588a7d55dedd687360c0a0ca6
font_02_sfnt_off0001195b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1195B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1