Malicious PDF — malware analysis report

Static analysis result for SHA-256 11bd5be92bd7d076…

MALICIOUS

PDF

73.3 KB Created: 2021-10-09 16:23:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 1c0894e3db42396f6176835a3a51ea39 SHA-1: ce057f2c33fb1cf3d588b17309b57a63989da784 SHA-256: 11bd5be92bd7d0764b9bdf20dd0f6483477d8974b53530d823cca4ad443f9dbe
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting, suggesting it's used to distribute further malicious content or phish users. The document body is heavily obfuscated, preventing analysis of its direct content, but the overall structure and URL analysis strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://techbis.pl/files/file/tekusarosogekaserog.pdf In PDF document text
    • https://inmaabiladi.com/userfiles/files/jemuwe.pdfIn PDF document text
    • https://sikdercollegeofpharmacy.com/scp/ckfinder/uploads/userfiles/files/81777618818.pdfIn PDF document text
    • https://eliteplacementagency.com/uploads/files/rovafodasejoxawa.pdfIn PDF document text
    • https://majubesar.com/contents/files/rizop.pdfIn PDF document text
    • http://purofirstli.net/userfiles/file/xukugamef.pdfIn PDF document text
    • https://sharjahcements.com/images/bulk_images/files/ribemitisegawak.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/39ffda8d2dfed22203f9bbc03ae3607b/noruwap.pdfIn PDF document text
    • http://cke.hk/userfiles/bewiveporefutujowemam.pdfIn PDF document text
    • http://vindindex.nl/images/uploads/bawifebijoxoj.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/2b5355d8254cc32dc7cda67e952a9095/visisizedixasesutojo.pdfIn PDF document text
    • http://cpils.com/userfiles/file/juxokudefevutulave.pdfIn PDF document text
    • https://viettincapital.vn/upload/files/tuvilejepolopodedivesan.pdfIn PDF document text
    • http://xsteelstock.com/d/files/55288509709.pdfIn PDF document text
    • http://fge-service.com/userfiles/file/39287630639.pdfIn PDF document text
    • http://shipsupply.ru/userfiles/files/36070705175.pdfIn PDF document text
    • http://grancanariacomercio.com/documentos/file/dejifowawujuzemovoviga.pdfIn PDF document text
    • https://nikoljski.com/ckfinder/userfiles/files/34413993539.pdfIn PDF document text
    • http://godsownproperties.com/userfiles/file/pidafadosurijerokuxo.pdfIn PDF document text
    • https://ego-sofa.tw/uploads/files/202109020447585318.pdfIn PDF document text
    • http://laclonghotel.vn/upload/files/58246725232.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144ba51e3296---68590499881.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=multiplying+square+roots+calculatorPDF 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_off0000b705.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB705 18392 bytes
SHA-256: dc02acc3cb0dc97466217b65d1d05ca52dc898a5522bcf4a059fd4374bc052e8
font_01_sfnt_off0000e6bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6BF 10904 bytes
SHA-256: d996ad2e1f9a18b59acaf7468ee51c3062b3b59920f7a7ce8a4f8accc9cf8326
font_02_sfnt_off0000ffd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFD3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1