Malicious PDF — malware analysis report

Static analysis result for SHA-256 10139d2fd4b0957b…

MALICIOUS

PDF

85.6 KB Created: 2021-09-02 08:14:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a107c12dff7cb77aa3a66e230960fe0c SHA-1: 8ed22264e48a9ec231a68e81805a3784d6ed05ca SHA-256: 10139d2fd4b0957b962c9295c7d6e3fbc7b4a9a1eb53c135e635e0f02642268a
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a significant number of embedded URLs, many of which point to compromised CMS upload directories. These URLs appear to form a link farm, likely for SEO manipulation or to distribute further malicious content. The ML classifier strongly indicated maliciousness, and the presence of numerous links to potentially compromised sites supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d9118c932f.pdf
    • https://ubranni.com/uploader/files/81070360835.pdf
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608941ca79e19---ralazafowa.pdf
    • https://nucamsa.es/userfiles/files/nexewidul.pdf
    • https://neksav.com/upload/ckfinder/files/66891605591.pdf
    • http://hosungtour.com/FileData/ckfinder/files/20210530_D1FB8F1ECCC420CE.pdf
    • https://gradeagroup.com/wp-content/plugins/super-forms/uploads/php/files/qhq7kq7u0tlr8f4kcrso6dvvh6/jixemidopidinipenujasegor.pdf
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160adc84b29585---jajagigomovedonuzuje.pdf
    • http://www.elitagida.com.tr/wp-content/plugins/super-forms/uploads/php/files/sph6e8skgqbq3g888k3dsc5il0/tiwixuzonimujeravokuk.pdf
    • http://beachfirebrands.com/userfiles/file/95458677439.pdf
    • http://bandenplaats.nl/cmsimages/file/kasapilalef.pdf
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/u27cc9ikfml7kagifih6d5amt2/74418113108.pdf
    • http://warraichmeats.com/wp-content/plugins/formcraft/file-upload/server/content/files/160714ba7528fb---kififakokonitiluxuzevesof.pdf
    • http://kqcme.yiaiwang.com.cn/upload/files/54465327970.pdf
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/9f5dbf5efa40dc9a16ca3e8bdf2757df/66810370497.pdf
    • https://havadisname.com/upload/ckfinder/files/tewezezukelawized.pdf
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/1ehtlmej3uvnb1tvpf1flm67k0/50572538317.pdf
    • http://dentish.ru/ckfinder/userfiles/files/wipivakuwabixizejomiv.pdf
    • http://www.annaleehuber.com/content_files/file/xirojuduxazuwepupafavojop.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609478888e450---sagubororolu.pdf
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca25cf2a5f---zixumojogulor.pdf
    • http://farmaciafici.com/userfiles/files/89607929350.pdf
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/e659c4e2f2f8c5b7584d040f97d817c0/pebalinife.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=starch+is+a
    • 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_off0000ea01.bin
377a16ccb631d6cb8eb9e3ca433c7f0a66eee95e4b9948b0ff13dccf7088c27e
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA01 18940 bytes
font_01_sfnt_off00011b21.bin
2d0fda3527fcf6d43dde34c805980a48a2ff32a4f76c8070af66ed5472cc9ce4
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B21 10000 bytes
font_02_sfnt_off00013169.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13169 16792 bytes