Malicious PDF — malware analysis report

Static analysis result for SHA-256 391bc2519eb9e03f…

MALICIOUS

PDF

68.7 KB Created: 2021-05-23 09:58:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 8a9813b7e0420d52f38368992d0fb0e1 SHA-1: f289798771f145324a30b9ad88f0b9cadf73c0d2 SHA-256: 391bc2519eb9e03ff4db45a7accee070cd340ba09fe3b317b3918e9921e39ca5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/91f479091e2c501417da981289e38d04/gaminavo.pdf
    • http://abapaposentados.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16090e23a0217e---4613268380.pdf
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/cb982db2bfc8e60659dac3f72d3d5b8e/wuzobozapapitakiludapezok.pdf
    • https://hogies.com/includes/template/uploads/file/zapimoderamijazoz.pdf
    • https://www.myjamaicais.com/wp-content/plugins/super-forms/uploads/php/files/314b826be88798551a2f04db189664ac/22059952782.pdf
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607b59fe8ccb8---37530789339.pdf
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/97446436c02ab56dcd034d2eb7a4745d/bevolosoba.pdf
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/c104340f123725232046abee6d896945/fexago.pdf
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6671507383---wawufu.pdf
    • http://hanhthien.net/uploads/file/29152470413.pdf
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/f800e1ddb8382c162935dcd8e24c1ded/91638531455.pdf
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160856a2df0b17---3012022807.pdf
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/90a09100d88dd35f215dd366b91349a9/mozakoditeneraso.pdf
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/s5i9kb24cachotnf4mdo7t6agv/zuger.pdf
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0673c2c6fe39429a6955535a73a21e72/97705450226.pdf
    • https://www.paparazzirestaurant.com.au/wp-content/plugins/super-forms/uploads/php/files/460468f3824cbb2efeab96624734b0fa/28904400050.pdf
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/160714d967fffa---3636954158.pdf
    • http://henri-ruch.ch/doc_pub/file/wisekap.pdf
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607d5b21af61b---riperodujinuxuteradu.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=nakamichi+tw211+true+wireless+sports+earbuds+review
    • 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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cf9f.bin
652a1862d5e8d2c24bf7cd320fcb32ca518f541255e3c496be88cc96e7e9c5dd
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF9F 5820 bytes
font_01_sfnt_off0000e36c.bin
04505e19025608fe098f951f5507cf20d4324572cd2a5b1d9b361cf350971563
pdf-font-stream PDF embedded font (sfnt) at offset 0xE36C 10108 bytes