Malicious PDF — malware analysis report

Static analysis result for SHA-256 1521053fd4dae8f2…

MALICIOUS

PDF

100.3 KB Created: 2021-06-26 05:43:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3a51c6d6a3a1ed711b4e0f095e04c4c6 SHA-1: e7c15d17f26dcaaa455e80de47329397f88574e0 SHA-256: 1521053fd4dae8f219860ac0607d14940e61753296ef864f58c78355e9628140
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs and links to compromised CMS upload storage, suggesting it functions as a link farm to distribute phishing or malware. The presence of embedded URLs and the nature of the heuristics point towards a spearphishing attachment attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9800

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 https://smidgel.ru/uplcv?utm_term=virginian+long+ride+to+wind+river
    • https://southtours.com/wp-content/plugins/super-forms/uploads/php/files/pj0ahu34bm82hg1h9og1u75cdk/fovarejekexuruzisada.pdf
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba17944ec67---97271530506.pdf
    • http://splogservice.ru/content/file/posixowivujol.pdf
    • https://www.idromeccanicasrl.com/idromeccanicasrl.com/wp-content/plugins/super-forms/uploads/php/files/d2e1420a0c10eeecd5e45d67d4fbbb1e/1267728238.pdf
    • http://mextro.de/upload/files/74577485053.pdf
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/fac193455e306c99f084df918a6fe62b/71129268028.pdf
    • http://k-yoga.org/file_upload/spaw_upload/file/20210601235135.pdf
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/mifjevtncmk17a6gs5ktrk32o1/bexisezuzolusaj.pdf
    • https://hizlipin.com/calisma2/files/uploads/87580149147.pdf
    • http://www.segurosfacility.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16070e9542313f---20308825369.pdf
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a63cedb39e5---tunerokesejogukutelujoz.pdf
    • https://tavio.ru/files/file/36799872476.pdf
    • http://interstyle.org/content/xuploadimages/file/juriru.pdf
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/74a972d280a6c330d905f598b9a183c2/fixulubu.pdf
    • http://harasim.cz/uploaded/files/30573120468.pdf
    • http://sdds.be/userfiles/file/89265461516.pdf
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/02f503584171a2311796e85d8e0663e0/garebuvokuwixenafafiga.pdf
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/sphedjtfnvdltgnt8vfu6b5rdp/pilifujazezizasonus.pdf
    • https://angelsstaff.com/uploads/file/sinojidamonogojixewuzow.pdf
    • http://novosib-sport.ru/ckfinder/userfiles/files/fowesipixaxuwetugozavu.pdf
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/1609fba80701de---wedamelokazaluwirana.pdf
    • http://sibmetiz.ru/upload_picture/26269556762.pdf
    • https://www.dolphinrfid.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609dc87655fe0---wilowaxibitovisedopam.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bf71e3320aa---15569986574.pdf
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/8b8fd92812f6c5e7af089816b23770f9/63619518773.pdf
    • http://sanitaerprofi.ch/fckeditor/editor/images/file/mularopufaliwimonevilu.pdf
    • 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_off00012605.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12605 16792 bytes
font_01_sfnt_off00013e17.bin
7b4c05a005464d0b69c0c3bd39cd74d76e896d57f79065adf7bb669d60e2fd6c
pdf-font-stream PDF embedded font (sfnt) at offset 0x13E17 17216 bytes
font_02_sfnt_off00016aca.bin
6ec78aef70842168469b4a0ee8bd8070f91a2d0f72f0f628ecf958e7d5c7ddd3
pdf-font-stream PDF embedded font (sfnt) at offset 0x16ACA 10376 bytes