Malicious PDF — malware analysis report

Static analysis result for SHA-256 9cd9bbad062aa313…

MALICIOUS

PDF

77.5 KB Created: 2021-06-09 15:45:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: 598806d3f62e2b106520fa44bc3b56bd SHA-1: a1ea0bfad94f7b75f61ea22fc6dc6988011455af SHA-256: 9cd9bbad062aa3132ee8a4a9d8624c8beba7c882f47c8db279b75cd2e2120ff1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document is classified as malicious by ML and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to numerous external URLs, many of which are hosted on compromised WordPress sites. The document body text, though partially obfuscated, suggests a lure related to "Tamil letter writing pdf", likely a tactic to attract unsuspecting users. The presence of multiple external links and the SEO poisoning heuristic strongly suggest this file is designed to redirect users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://cructi.ru/uplcv?utm_term=tamil+letter+writing+pdf PDF link annotation
    • https://aquafilling.com/userfiles/file/37669333159.pdfIn PDF document text
    • https://www.rowtheerne.com/wp-content/plugins/super-forms/uploads/php/files/5a273d81d708530ffbc68ac4916428f2/2803052127.pdfIn PDF document text
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/cgmf40jkq12t9r1bf5pj0o9f12/bopemafozivelojewexe.pdfIn PDF document text
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1608a809f5133d---37076364311.pdfIn PDF document text
    • http://auxerretv.com/content/public/file/kuvolirutiberoj.pdfIn PDF document text
    • http://sva-jeanroze.com/xmedia/file/71562568767.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609f90bd3271f---jikodewuvomu.pdfIn PDF document text
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608f71681794e---tosipafarutu.pdfIn PDF document text
    • http://alimentosldm.com/userfiles/file/molinulexuzadu.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16080447779ce4---kesekuxanu.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/41gltit852v36klclg9s7aeih1/88481941183.pdfIn PDF document text
    • http://espacioschillout.es/images/admin/file/16903115244.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad59cecdb88---32427988697.pdfIn PDF document text
    • https://acornschoolcharleston.org/wp-content/plugins/super-forms/uploads/php/files/5ecedaaa662fa99f4e237014fb21f4bf/51595279025.pdfIn PDF document text
    • https://www.themeshcowork.com/wp-content/plugins/super-forms/uploads/php/files/f1c331d00d0d791e9e29366e6e80c7db/71609937780.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e79e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE79E 4904 bytes
SHA-256: b8bbf85751ea1aec5a9255cd092823be262e2f7efaacb0e1594ae4ad36e833dd
font_01_sfnt_off0000f837.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF837 10308 bytes
SHA-256: cc6f43fa4372665eb9706e39995d08d983a0bc4772c9f4a269b21e2c62df4390
font_02_sfnt_off00011b49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B49 4324 bytes
SHA-256: 1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e