Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a11c50c3414a1c8…

MALICIOUS

PDF

84.4 KB Created: 2021-09-08 11:45:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a6a41953f8ebca3c6b417da6a80613cd SHA-1: fa9e11456c62928687dfb4e7b04cc34b4846f223 SHA-256: 8a11c50c3414a1c89eed14b44a1cc092e88b9576b64065992b0bfc6914be5e06
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL analysis and heuristic firings.

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://bugaboo-buffalo.eu/UserFiles/File/gavenilemali.pdf In PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1608b82b683955---58960455820.pdfIn PDF document text
    • https://doxity.ro/ckfinder/userfiles/files/25571438864.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160800405d5a38---buxojexetanog.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16071adcd2eeeb---pavuwepopunivixe.pdfIn PDF document text
    • http://styropapex.pl/userfiles/file/27658985575.pdfIn PDF document text
    • https://dailyhondaotomientay.com/upload/files/68455244818.pdfIn PDF document text
    • http://libertyquad72.fr/userfiles/file/9646684094.pdfIn PDF document text
    • https://audit-advisers.com/userfiles/file/gifuzun.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160adc4ceb2380---21665770160.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9dd4c39bbc---vetosepewofinosurabuxexip.pdfIn PDF document text
    • https://matfreklam.com/calisma2/files/uploads/dokebilekulureku.pdfIn PDF document text
    • https://tepihtrava.rs/files/nikofeloxojo.pdfIn PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16121515a7c211---jomakosomadafutasisarareb.pdfIn PDF document text
    • http://portalcom-b2b.es/img/user///file/_0139701001623926062.pdfIn PDF document text
    • https://bold-iot.com/uploads/files/202108211105045434.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bef006312f9---zidedi.pdfIn PDF document text
    • https://eyescare.vn/app/webroot/upload/ckfinder/files/96029434175.pdfIn PDF document text
    • http://verynailscm.com/user_img/file/2389863164.pdfIn PDF document text
    • http://joy05.com/_UploadFile/Images/file/8508951952.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210623215451659.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a4c5a5c262e---90339471144.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1611d41c7e04f2---33249606206.pdfIn PDF document text
    • http://lakehighlandsrw.org/clients/863582/File/jobeken.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=tratamiento+de+la+gastritis+por+helicobacter+pylori+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_off0000e0ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0EF 18812 bytes
SHA-256: 4944f1cbc5bf941098dda52f18111eabc46485c294087e941c021fa397664c67
font_01_sfnt_off00011173.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11173 11284 bytes
SHA-256: 072d5f1c02efe6c08ab695787ed5b553daff496f78356432c9c3cb1eb1f5db61
font_02_sfnt_off00012b55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B55 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1