Malicious PDF — malware analysis report

Static analysis result for SHA-256 7636f441146a3c23…

MALICIOUS

PDF

86.7 KB Created: 2021-07-01 17:59:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f6b3f2e9760e052d3424361c22f1ce16 SHA-1: 6a466d0b6d5e9207e60b86848158b0f3bf38d235 SHA-256: 7636f441146a3c2379656e17e40f09a339b86adf3827257ca37b968f63b06ee2
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier indicating a high probability of maliciousness. The file functions as a link farm, directing users to numerous compromised WordPress upload storage locations and disposable hosting sites. These links likely serve as a distribution point for phishing content or further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://accu-chek-event.com/ckupload/files/27649196830.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d7d2b5d5df---12526914761.pdf
    • http://stardentalcare.org/userfiles/file/veluwoboz.pdf
    • http://baobiachau.com/luutru/files/60925878789.pdf
    • http://amazingindiaphotos.com/amazingindiaphotos//upload/fckimage/file/72450819778.pdf
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/160908f166b337---52941455062.pdf
    • https://charlesstreetvideo.com/userfiles/file/1026459422.pdf
    • http://strechybenesov.cz/content/95739956284.pdf
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608510bd44c1e---41885347871.pdf
    • http://w-f-l.de/user_img/file/38144228791.pdf
    • https://www.eziblank.com/wp-content/plugins/super-forms/uploads/php/files/71cb7d5b708b1314c857a11037701c74/xegeduvukorodisubeganidar.pdf
    • https://wecafephuket.com/wp-content/plugins/super-forms/uploads/php/files/ij3oip4fabftjn3do74t7jvob1/tonivi.pdf
    • https://churchofgodinjamaica.org/app/webroot/files/mewefegorivubovudi.pdf
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c4b84ca5d5---narowewenofemetaje.pdf
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/30d0457b6fa4b6c9b827c73d52d4a4ae/93880830841.pdf
    • http://m2m2design.com/userfiles/ponib.pdf
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/21f498e790aa4dbbb78b64394728b3ed/94675932270.pdf
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1608952e8d9704---46060259033.pdf
    • http://flirdining.com/uploads/files/jizoxexif.pdf
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/46acmi543o6ev01k0qfak22sip/28992436008.pdf
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c610a35af4a---xisapuzi.pdf
    • http://jatyn.cn/upfiles/202105/file/1621028952.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=defence+to+defamation
    • 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_off0000f0a5.bin
4388a0cc0a0362533aad83f1edf51db511ad712372b69d565465bc5c9ed3a08f
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0A5 17548 bytes
font_01_sfnt_off00011e75.bin
0c279f78e279052ea3347b604f3abf6c639983b6ad8acfaa422c431170cd808c
pdf-font-stream PDF embedded font (sfnt) at offset 0x11E75 10324 bytes
font_02_sfnt_off000135bb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x135BB 16792 bytes