Malicious PDF — malware analysis report

Static analysis result for SHA-256 8e549c660745a4df…

MALICIOUS

PDF

71.2 KB Created: 2021-09-02 03:16:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 34c5800d35b8425bb794f30e05bcdfc9 SHA-1: 17203744d41d2b48a5f150aedef92c4c0bced2b9 SHA-256: 8e549c660745a4dfd05c1b553eb8030d974268d7839e52287e94219680b0ded4
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs pointing to compromised WordPress sites, indicating a link farm or redirection scheme. The ML classifier strongly flagged this PDF as malicious, and heuristics identified it as a link farm on disposable hosting. The primary purpose appears to be directing users to external, potentially malicious, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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://philabc.ru/uplcv?utm_term=integrated+science+multiple+choice+questions+and+answers PDF link annotation
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e356126999f---49473661420.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/9e7c70357c71aba6942980e1b105e909/325036887.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dcdf009d68---vojumoman.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16088914ca8651---zofefawe.pdfIn PDF document text
    • http://hengfengpaper.com/filespath/files/20210730022620.pdfIn PDF document text
    • https://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/29992a6c74b37ffdfa8567f4398f7ce0/74907836004.pdfIn PDF document text
    • http://alphasigmaoverseas.com/userfiles/file/bepimuzepakobad.pdfIn PDF document text
    • http://www.macrolepidoptera.hu/userfiles/files/siromawivelix.pdfIn PDF document text
    • https://roeveragri.ac.in/wp-content/plugins/super-forms/uploads/php/files/80c5745754e7c197f85654947525555b/31106327839.pdfIn PDF document text
    • https://mm-podium.ro/userfiles/file/nekogovez.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f8e0b1b78bf---36723025324.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/a825aaad44bfe78e45592a689e680b5e/64879762904.pdfIn PDF document text
    • http://ngnjl.com/userfiles/files/43384381381.pdfIn PDF document text
    • https://www.harasportcenter.com/wp-content/plugins/super-forms/uploads/php/files/riekddmaano714qtn1qg8pk0br/fexojesezuweritade.pdfIn PDF document text
    • https://angkortaxiservice.com/userfiles/file/37685094206.pdfIn PDF document text
    • https://youkuvpn.com/upload/files/72459846043.pdfIn PDF document text
    • http://viettelhaiphong.me/data/dulieu/files/kaforapulase.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160e77258bf65e---59020333700.pdfIn PDF document text
    • https://gadesign52.com/uploads/files/202108280305198797.pdfIn PDF document text
    • http://constantemail.com/userfiles/file/16235485567119343437.pdfIn PDF document text
    • http://westmont1970.com/clients/1/1d/1d0046bffbd1a03ca32bb02538d2ceaa/File/43708954319.pdfIn 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://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_off0000b5c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cddd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDDD 11244 bytes
SHA-256: 4546f9a0b05ffbb2053aa6afd7984a8ab379cfdc1ca55874567ef429dc057e74
font_02_sfnt_off0000e78d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE78D 15676 bytes
SHA-256: 6c6f322b32eb018173bbe6a24d1ea22c6c322bf407648a1d0c2d1d29f2e97263