Malicious PDF — malware analysis report

Static analysis result for SHA-256 87170a3de791e3d0…

MALICIOUS

PDF

78.5 KB Created: 2021-05-03 14:12:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: a20e685b0f8a82916142730282d5108b SHA-1: bd4cc7ae872ea3dfaa050cb97e14501337ecf023 SHA-256: 87170a3de791e3d01497041f47c14f8f8f06a57fb40014f8174f0b9dc9786f74
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple URLs hosted on compromised WordPress sites. These links likely serve as a lure for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/g2rsqpm56m6lt0otki88mbrbgr/sakozafan.pdf In PDF document text
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/dbnthpr3lls5qg3snhqar3jgap/matalemidateresaw.pdfIn PDF document text
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/1e2dba5e945481b98b9e77b46a458465/pegamadomonasemodofuduna.pdfIn PDF document text
    • https://criteriacambio.com.br/wp-content/plugins/super-forms/uploads/php/files/co8l3rdit0r8jvefh3b6h3092b/zesozo.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/u7omd24psipi01ep3kubhna06r/1310895561.pdfIn PDF document text
    • https://thetitangroup.ca/wp-content/plugins/super-forms/uploads/php/files/e12e7558b9f2a307448eda92d300d4ce/34714701031.pdfIn PDF document text
    • https://micast.de/wp-content/plugins/super-forms/uploads/php/files/2an2fa451825o24cbbd99dlilc/pirevadevop.pdfIn PDF document text
    • https://airbays.com/userfiles/file/6047059986.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16087da2bee725---xulapalolesusebiditufeje.pdfIn PDF document text
    • https://ethiquedevelopers.com/wp-content/plugins/super-forms/uploads/php/files/396c1057f1e5f306b0f5e9d0f7b7857b/vesopatamifaj.pdfIn PDF document text
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/b22686af52d16b52ff084d3e0a3b530d/44077129422.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/af54k24jog9rgatk81mj3k8m8h/39067788383.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607dbbb3e137b---60009305396.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16072b033889bd---jorug.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=states+of+matter+chart+answersPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f70d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF70D 5284 bytes
SHA-256: dcbd92557e474e2e538c20f5cb66d5f7e8cae9f8f4883446ac0b48fe1bac8049
font_01_sfnt_off000108e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108E9 10664 bytes
SHA-256: dd4a2efa048bb85a944492d82d69b8d83a0394e93151a10ced5385dea93a000b