Malicious PDF — malware analysis report

Static analysis result for SHA-256 20856a71c4da8462…

MALICIOUS

PDF

81.9 KB Created: 2021-09-05 03:34:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 01e11d20ee689aba36bea4583416925a SHA-1: 6fb1cc321eb0808058a58244e84a55a25169dc6a SHA-256: 20856a71c4da8462042ac29afdf03ac1d4b6e944354a451b0bc9c9c97794a729
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a phishing or trojan threat. Heuristics reveal it functions as a link farm, containing numerous URLs pointing to compromised CMS uploads and disposable hosting, likely to redirect users to malicious content. No scripts were extracted, and the document body was unreadable binary data, limiting further analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://pivotal-technologies.com/userfiles/file/32883394328.pdf In PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a96b62ee33c---40294392131.pdfIn PDF document text
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/2c024be5c3d57f96b8cd7f4cdf304cc9/76402302465.pdfIn PDF document text
    • http://thietbianninh188.com/uploads/files/3328336355.pdfIn PDF document text
    • http://www.dkmodels.net/ckfinder/userfiles/files/24471385787.pdfIn PDF document text
    • https://www.frontieregypt.com/sites/all/libraries/ckfinder/userfiles/files/14248393136.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/turarovuxito.pdfIn PDF document text
    • https://bandotrading.com/uploads/file/95850896186.pdfIn PDF document text
    • https://maviet.vn/upload/files/655957143.pdfIn PDF document text
    • http://hanart21.com/files/userfiles/file/13370001505.pdfIn PDF document text
    • https://abouelhoulgroup.com/userfiles/files/ratepoleso.pdfIn PDF document text
    • http://bawaconstructions.com/editorData/file/favobofa.pdfIn PDF document text
    • https://lightspec.com/wp-content/plugins/super-forms/uploads/php/files/145fb5cc0b4e3e14b1e5c4176dac8fe2/zumotirupenevoxu.pdfIn PDF document text
    • https://satnamunicipalcorporation.com/admin/ckfinder/userfiles/files/refukuj.pdfIn PDF document text
    • https://binarbaidrealestate.com/public_html/userfiles/file/ganesolinirot.pdfIn PDF document text
    • https://ipssecurityconsultants.com/ckfinder/userfiles/files/36447281986.pdfIn PDF document text
    • http://vamaconsulting.sk/userfiles/file/13634997649.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/67d72ea739fd3358e8c6a97276861881/66497426657.pdfIn PDF document text
    • http://paglialonga.it/userfiles/files/wefufanimiguxem.pdfIn PDF document text
    • https://liantoong.com/archive/upload/files/nuwob.pdfIn PDF document text
    • https://www.micron21.com/application/third_party/ckfinder/userfiles/files/72340191692.pdfIn PDF document text
    • https://vivekanandbawwa.com/userfiles/file/sewubaja.pdfIn PDF document text
    • http://3e-recycling.ru/app/webroot/filesfiles/11342184069.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=detail+in+contemporary+bathroom+design+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_off0000dbe4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBE4 11320 bytes
SHA-256: ab64d7f5cd8c3898c82f25fa182fd8be6b3f3d5e743515eed3d9273e1457acd9
font_01_sfnt_off0000f5db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5DB 16804 bytes
SHA-256: 5db4fc555de20fe1398140bb8ceb99de9794e512a33583cae3ec2c2863eb6aa9
font_02_sfnt_off0001217e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1217E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1