Malicious PDF — malware analysis report

Static analysis result for SHA-256 ea319eb558da2e6f…

MALICIOUS

PDF

84.7 KB Created: 2021-06-28 12:46:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9e8713458ac7ccd489c7eaab2d63a80f SHA-1: 6bd3ab84127f9923f7e26973508982ef249bcc62 SHA-256: ea319eb558da2e6f4cb8bc90de9732c94416082fc923c321266531734f47a433
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised CMS upload directories, indicating a link farm designed to host malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The presence of multiple compromised domains and the structure of the links point towards an attempt to obscure the true destination and leverage potentially vulnerable WordPress sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0c47902767---96417708124.pdf
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/160983c860280a---82251338284.pdf
    • http://tamker.hu/userfiles/file/betegodonirimaso.pdf
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/17c3b1f295cbf00c411398e01e37678c/87459427240.pdf
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/160b3bf8ce5efe---dikikojozidejikugekuru.pdf
    • http://ricarda-allegra.de/userfiles/file/lipejomubunotadiwidudewek.pdf
    • http://servis-hradec.cz/files/file/xasonewijupuviwokazazipu.pdf
    • http://volamtuyetthe.com/userfiles/file/dajaxodojos.pdf
    • http://gaongonmaiphuong.vn/webroot/img/files/pigodiwibegodolito.pdf
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8e3420b81---10209454551.pdf
    • http://sarlampa.ru/upload_picture/vasolimitegi.pdf
    • https://anaksemut.com/contents//files/lufosekamikuxare.pdf
    • http://zawayakw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d4d0374cf9---45404642594.pdf
    • https://www.aceitedeoliva.com/wp-content/plugins/super-forms/uploads/php/files/88bba16566a4768842e081bd42d625da/42938515151.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608390a3a009f---raxilubenederoribivumo.pdf
    • http://www.rkcomdesignservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098e74fa4503---najikegux.pdf
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/96ec768f07ac9a3012f2b809daa25aca/26350069776.pdf
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160cecd1f74321---39649945163.pdf
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e8b3534d95---64028533265.pdf
    • http://nenkin-t.com/upload_img/ck/files/xonosom.pdf
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/8guvsng6odb8421jmoc3s3pl9f/80407736900.pdf
    • http://kantoromega.pl/userfiles/file/feliwovimilemi.pdf
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086ba1688890---32953623276.pdf
    • http://apvn.info/userfiles/file/19256126723.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+calculate+afc+and+avc
    • 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_off0000e79c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE79C 16792 bytes
font_01_sfnt_off0000ffae.bin
a768416942992a1f24d6492c7241e75d8d6d5351fbfeef2bec388b6c7a92a705
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFAE 17556 bytes
font_02_sfnt_off00012e05.bin
24df752f265d8a82d5f7a56db839316c812f7b857fe94fe3ec887a50fdeedcd6
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E05 10352 bytes