Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5c5c999a9168298…

MALICIOUS

PDF

81.2 KB Created: 2021-06-15 15:56:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: a0cec6baa50a7230e12e6a16f0a91fab SHA-1: ad52b3b43dbcc85e9fa7f39130428db0235a8a59 SHA-256: b5c5c999a91682985adf85b9238081e48a490e5f4fd81a64c612315082add680
164 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to WordPress sites utilizing form plugins for file uploads, suggesting a link farm designed to distribute malicious content. The presence of a 'download button' heuristic further supports the phishing lure. No scripts were extracted, but the overall structure and URL patterns are consistent with phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://wastran.ru/uplcv?utm_term=best+smudge+brush+procreate PDF link annotation
    • https://www.engltg.com/wp-content/plugins/super-forms/uploads/php/files/0623ed0bf66caa363a849527f4d008f2/loxazexopiwipatudofo.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076f79b44457---31975669141.pdfIn PDF document text
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa35b3727f3---mitediwenivenubi.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16073488ca8afc---jamatulewisezak.pdfIn PDF document text
    • https://porterbrothersltd.com/app/webroot/uploads/86649116813.pdfIn PDF document text
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/8a0snhbifk0k52a3tju1getqe9/fepivegepegezarufibef.pdfIn PDF document text
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/e4dbd7f8a35b8965c98b4abfb32b44c8/vesok.pdfIn PDF document text
    • http://anhuishangbiao.com/upload_fck/file/2021-5-23/20210523220126105297.pdfIn PDF document text
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c11b03e2b49---97287463919.pdfIn PDF document text
    • http://zulassung4you.de/bilder/file/rusosi.pdfIn PDF document text
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/c09917ef34e709112ac71e9ec0edbb38/vuwukidivifuw.pdfIn PDF document text
    • https://canadianrelocation.net/wp-content/plugins/formcraft/file-upload/server/content/files/160914b6a8f9de---54323549539.pdfIn PDF document text
    • https://www.basur-tedavisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f4bdf70c9b---86293044539.pdfIn PDF document text
    • http://somsit.com/ckfinder/userfiles/files/80270364750.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010033.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10033 5644 bytes
SHA-256: 83b91c9c7e142d6ae08ad6ae92d87752bcc77c7f12f586338bb617e9bc9de458
font_01_sfnt_off00011330.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11330 11336 bytes
SHA-256: c8ec8011df92f116b1a85cd287bf7ddb34e5e681d8bf30727de1c71870d61e22