Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf35da3018f0a034…

MALICIOUS

PDF

83.3 KB Created: 2021-09-07 12:06:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 291216790384ebdebce3689e73dff63b SHA-1: 43b742d6821d32108d17a836f780a22db341e896 SHA-256: cf35da3018f0a034fe3982a0c20414361bbc51af1b224827cbef095363c14c5c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The presence of multiple compromised URLs and the nature of the link farm point towards an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/78cee653ecf0a7c2f85d146e13932a91/66795046147.pdf
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/161169939a34e5---8264109135.pdf
    • http://polipack.ru/content/file/foxarinuxugi.pdf
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d5784e25334---33047325526.pdf
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/f92ffe50d67eb884c69e08777d8a4f12/5426494958.pdf
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9ae5ab2682---falosotefapasaremej.pdf
    • http://osoboebludo.com/ckfinder/userfiles/files/41615912061.pdf
    • http://domeinbeverdonk.be/assets/files/file/fanodinemojinajutubopu.pdf
    • http://somogroup.vn/ckfinder/userfiles/files/51845991315.pdf
    • https://vidaleve.ind.br/ckfinder/userfiles/files/89821876525.pdf
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613713c9b1ba7---bojafupogifol.pdf
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/153aaf8f5982b85ae66a119b0fc6c6b9/mibaxidafivuwovuzuxevusak.pdf
    • http://www.colegiometa.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160c68118e4ab9---lilapi.pdf
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/160948809a7c47---nebopapemifabaxafom.pdf
    • https://vinniescustoms.com/userfiles/files/7465044752.pdf
    • http://busankid.com/webfiles/board/file///77160950523.pdf
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/06f0d3db6ea271c32b25217fd8d3a537/69780953952.pdf
    • http://janjoling.com/public/ckfinder/userfiles/files/tofivobakowisojekagipit.pdf
    • http://jatyn.cn/upfiles/202105/file/1620362426.pdf
    • http://joewhitefamilysite.com/clients/59967/File/57449559488.pdf
    • https://landtop.com/filespath/files/20210824110154.pdf
    • http://ues-rb.ru/themes/ues-rb.ru/files/76435821386.pdf
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16115f19af3275---vizexeribifor.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=mordiendo+manzanas+y+besando+sapos+pdf+gratis
    • 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_off0000dcc6.bin
b36dc3425d6396133fb114bb5c66c3896e91972a64c3ee4f54a9791321d0c7dc
pdf-font-stream PDF embedded font (sfnt) at offset 0xDCC6 19180 bytes
font_01_sfnt_off00010dd8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10DD8 16792 bytes
font_02_sfnt_off000125ef.bin
7f07b27fc654eb3f4dd1808f1819d3ee7c5f33750bf63e30b7621ebaa541475d
pdf-font-stream PDF embedded font (sfnt) at offset 0x125EF 11100 bytes