Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b1150881d57c843…

MALICIOUS

PDF

83.2 KB Created: 2021-09-04 18:35:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: ce60525cc58c701c7b219b8dba06c9fb SHA-1: 8eb98de1cd4654b1e67ee21e0434e5d38e618baa SHA-256: 5b1150881d57c843893fa9e4c5d67164a737a8d4829f8e9a020476e0da3b93ea
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised CMS uploads 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. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://cnokorea.com/userfiles/file/jegoxenorubigekerik.pdf In PDF document text
    • http://www.hausbaumesse.at/ckfinder/userfiles/files/90030398078.pdfIn PDF document text
    • http://riggi.ru/userfiles/file/padutowijefujolunukeb.pdfIn PDF document text
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/4d8995e39312e4b3b1b6c0456bab7cae/rosop.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/0de965f9841294292fe3cec5b440355e/27731998827.pdfIn PDF document text
    • http://ellev.fr/upload/files/wirun.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/e788a0e7ac42a04b9e64b8bd10931cf0/zazer.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/914f4efce9b3712207e51822703f7362/88764194967.pdfIn PDF document text
    • http://parentini.it/userfiles/files/17395951903.pdfIn PDF document text
    • https://smartcirclegroup.com/userfiles/file/linamukorozufavozalel.pdfIn PDF document text
    • https://www.propertyfilevault.com/wp-content/plugins/super-forms/uploads/php/files/86f5d04305a1ee0f8a6f9b4feb9cad95/wenanilofo.pdfIn PDF document text
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c573b99a947---bedinaka.pdfIn PDF document text
    • http://profitoolinfo.ru/ckfinder/userfiles/files/28300335228.pdfIn PDF document text
    • http://www.pavimentosyreformasferlu.es/ckfinder/userfiles/files/matonupobesurep.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/32343841471.pdfIn PDF document text
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160755e3c376bb---mobobifes.pdfIn PDF document text
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/9e43007c1657c41ea56dbccec572f568/53385750641.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1609105d635568---mepuwuz.pdfIn PDF document text
    • https://estudiowebcolombia.com/ckfinder/userfiles/files/91511215939.pdfIn PDF document text
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a5d0881625---90110907029.pdfIn PDF document text
    • http://w.scenekunstskolen-efteruddannelsen.dk/ckfinder/userfiles/files/3396317237.pdfIn PDF document text
    • http://yuha.be/_files/file/34589592549.pdfIn PDF document text
    • http://photo-preiss.com/upload_files/files/11007568907.pdfIn PDF document text
    • http://www.c-l-r-p.com/admin/ckfinder/userfiles/files/zerugajuxuzatasadi.pdfIn PDF document text
    • https://whitesal.com/data/images/file/9173_20210518000221.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=reading+and+writing+targets+3+student+book+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_off0000deea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEEA 11264 bytes
SHA-256: 341b83617803b9c77ac94d40016a93145bc57613341b5ad416e9a8ea57361f41
font_01_sfnt_off0000f91e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF91E 17480 bytes
SHA-256: 227acc02627bf5bf2983f27d596db59f41f339b191c97aceaa41fc8b43b29f33
font_02_sfnt_off0001267d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1267D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1