Malicious PDF — malware analysis report

Static analysis result for SHA-256 25a50c85198e68f9…

MALICIOUS

PDF

73.1 KB Created: 2021-07-15 10:38:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f967a34121b44d8e32f8602879e87de5 SHA-1: 2b4a743125dfd3161931a45a4bd6a89ece1ce749 SHA-256: 25a50c85198e68f9337dc22521e97a397df77c73ed9cf4f79fd221b5d11069f4
96 Risk Score

Malware Insights

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

The ML classifier strongly indicated maliciousness, supported by heuristics identifying the PDF as a link farm pointing to compromised CMS upload directories. The document body is unreadable, but the presence of numerous URLs, many hosted on compromised WordPress sites, suggests a phishing or content distribution scheme. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/e33d093e67dda8ef2b6b34080cf2e6db/85328881241.pdf
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/160bdae33e381d---xedagijirevafol.pdf
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ec436aa60ed---mewawosokes.pdf
    • http://rideabikenews.com/user_img/files/juwanavamaverekotajufisus.pdf
    • http://architettotoma.it/userfiles/files/tifijidiwovibejisedozulot.pdf
    • https://pensionatiitalianiinportogallo.it/wp-content/plugins/super-forms/uploads/php/files/14d4d3a84c3dc4d53be29aac159cec9f/dukilefexuvukajep.pdf
    • http://quickvideo.nl/userfiles/file/fabisepiwegilone.pdf
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c6af0a3090---61505756155.pdf
    • https://amenajarisiconstructii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608b5d306531a---13248039497.pdf
    • https://traonguoc.vn/wp-content/plugins/super-forms/uploads/php/files/9maggj6oi030pgv18m66c5v2cc/vadowi.pdf
    • https://www.marvistasales.com/wp-content/plugins/super-forms/uploads/php/files/1b291c20ffb5a0790fb5a0b72521674e/63885822318.pdf
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/2675hqufpm5rr1hlcfp0p26bm6/61296221867.pdf
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070db0935172---90122205853.pdf
    • http://analogsys.com/uploaded/file/196955641760913173be706.pdf
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/hakdgfk3ql9erru1p7ku3fke62/fimenemukari.pdf
    • https://pet-fashion.ro/mm/file/vilapoduberurux.pdf
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/160820ddf10940---pesaliwafosotovitufomim.pdf
    • https://yucekalipmakina.com/tsrm1/img/userfiles/file/86778383806.pdf
    • https://crownprolaw.cn/userfiles/Proj_Name//files/73457809418.pdf
    • https://xn--arbeitskndigungsrecht-best-5zc.de/userfiles/file/sapubiret.pdf
    • http://johndanton.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/24278907702.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=canker+sore+tagalog
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bcfc.bin
2bbdb71b3ac8315f8199063a8f5e7ec5034f2185ac9a68a99da102fa3adb0b23
pdf-font-stream PDF embedded font (sfnt) at offset 0xBCFC 16548 bytes
font_01_sfnt_off0000e827.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE827 16792 bytes
font_02_sfnt_off0001003e.bin
727956feab9855f28fc88f9bc7dbf31b6ae2660adc9b63790d370c8643cb329b
pdf-font-stream PDF embedded font (sfnt) at offset 0x1003E 10312 bytes