Malicious PDF — malware analysis report

Static analysis result for SHA-256 87f9cb6d93be9d38…

MALICIOUS

PDF

97.4 KB Created: 2021-09-08 23:33:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 87a5b9af0592bd12f57b18590c0b513a SHA-1: 1269fc6abec310c52875e56dd7b5f1517450002c SHA-256: 87f9cb6d93be9d3842496033890f1574e6286e49257ebfc7a54247ecd96b5f1d
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. Multiple heuristics indicate the PDF contains numerous links pointing to external websites, many of which are hosted on compromised WordPress upload directories. The primary purpose appears to be directing users to potentially malicious content through these compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

Heuristics 6

  • 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.
  • 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://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137f9572fb2a---kimewefitotunotigomotupa.pdf
    • https://dacola.com/upload/files/vurebanazosabumazajuged.pdf
    • http://www.yankey.com.tw/demo/public/editor/ckfinder/upload/user_upload/files/dufas.pdf
    • http://japan-railpass.info/images/blog/file/mawarakemizuwebibazarir.pdf
    • https://gamepinleri.net/calisma2/files/uploads/52324655342.pdf
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/1612faa2b3e139---mozapekotofili.pdf
    • http://musorcentrum.hu/files/article/file/98536643537.pdf
    • https://luxurybaths.marblobaths.ph/app/webroot/img/files/99138875627.pdf
    • https://menu2uplus.com/images/file/77527259517.pdf
    • https://cualuoihoanmy.com/uploads/userfiles/file/56949254159.pdf
    • http://perfectionistpaintingnj.com/ckfinder/userfiles/files/73978040467.pdf
    • http://mdsalon.ru/img/lib/file/mexewawixapitemepubef.pdf
    • https://un7un9b3rl1pa7-99.com/contents/files/88239161625.pdf
    • https://actsonics.com/uploads/files/202109061907026062.pdf
    • http://www.farmaciavictoriayjmleon.com/userfiles/files/5256240536.pdf
    • http://sarkar.ie/userfiles/file/dilakor.pdf
    • https://mabuksusu.com/contents/files/regofapina.pdf
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/eae46d2d1331d96a3f30c8bc1f71a3dd/woxinukegos.pdf
    • http://irina-beha.com/ckfinder/userfiles/files/nawokigajopiwopuk.pdf
    • http://tinhdauvietnam.vn/upload/files/gujenawomimoju.pdf
    • https://giant-nano.com/app/webroot/userfiles/files/tewum.pdf
    • https://www.moxiclear.com.au/application/third_party/ckfinder/userfiles/files/85274153273.pdf
    • http://fixafilm.se/userfiles/file/7097595313.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=123movies+mamma+mia+here+we+go+again
    • 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_off00010f04.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F04 16792 bytes
font_01_sfnt_off0001271b.bin
f5e7d810b63142827f457f64199b33316e2c667d9087e676bf0f9195d3709f48
pdf-font-stream PDF embedded font (sfnt) at offset 0x1271B 10808 bytes
font_02_sfnt_off00013ff4.bin
4aba5f054a00cac8ae16265737949bd5105fc7089af891bcadf25f8b2feb3999
pdf-font-stream PDF embedded font (sfnt) at offset 0x13FF4 21208 bytes