Malicious PDF — malware analysis report

Static analysis result for SHA-256 403437a4591798d7…

MALICIOUS

PDF

80.9 KB Created: 2021-07-24 09:31:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3fd3c3056208bec3e483580a3f8e6a04 SHA-1: cc97681b0451f0e966c3bd2fea8d37eba012a397 SHA-256: 403437a4591798d704e49713652df62eaccf2746252c7442a4e79a9d2f45d36b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and a link farm pointing to multiple distinct hosts, many of which appear to be compromised WordPress sites, suggests an attempt to redirect users to malicious content. The primary attack pattern involves leveraging these links to deliver a secondary payload or conduct phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/160876a2b165fe---mubizazepag.pdf
    • http://maychamsocda.vn/images/userfiles/file/38968001867.pdf
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/160a1b6894ba13---46403267802.pdf
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/1q2o471lr6lm8qefe5ltfnfeeq/27359023944.pdf
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/lqcj3qv87l0u9iin67o87ce8r4/66470615960.pdf
    • http://redfordunion70.com/clients/869360/File/44399245981.pdf
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/t1lbecrs224rfdep51v7e8ro7f/98563456552.pdf
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/d6a9d72d2fd83789b08f3ec93af5d698/32483572679.pdf
    • http://consade.com/userfiles/file/2985832120.pdf
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/b9ae17603a7390c3a345da5529b37ff1/xavedafowomemi.pdf
    • http://taiwanglassgroup.cn/userfiles/file/sivanapebaduparivif.pdf
    • https://kimtuong.vn/isc/public/files/fckupload/file/13985401867.pdf
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081a87bc97b7---93567925627.pdf
    • https://accuratesearch.com/userfiles/file/lowugor.pdf
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/dc200bf13d5049050620885c52cd62b4/sepokobaropud.pdf
    • http://friend5190.xyz/js/ckfinder/userfiles/files/zirefonozasumot.pdf
    • http://zge-led.com/luodan/images/userfiles/file/ziwisufegibi.pdf
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/ce04b55aa36e888402894ea698ceee5a/nelakej.pdf
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/160c5840881fbc---lafaxasadeposek.pdf
    • https://ehblending.com/wp-content/plugins/super-forms/uploads/php/files/9d5d864792396050ec5c4202d05bd00e/99202321116.pdf
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160f228e027cbc---93718136705.pdf
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/55f8287b718c434b6b1149e916f4ecf8/53472840094.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160835f2d0d1ed---kizafigikixikejavup.pdf
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b04b295b5be---gafakufetovugefopabuxazu.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=9.s%C4%B1n%C4%B1f+kuran%C4%B1+kerim+ders+kitab%C4%B1+cevaplar%C4%B1+korza+yay%C4%B1nc%C4%B1l%C4%B1k
    • 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_off0000d2e5.bin
e161f97af7017e667de09c1adeaf97be1044f4625cec4aaeab8cddfb0125960c
pdf-font-stream PDF embedded font (sfnt) at offset 0xD2E5 17796 bytes
font_01_sfnt_off0000fe39.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFE39 16792 bytes
font_02_sfnt_off00011650.bin
2c8378654b8b64a997f0bc6baac0a9f8a08c80a8f098b96717dca86fdddddaf5
pdf-font-stream PDF embedded font (sfnt) at offset 0x11650 11536 bytes