Malicious PDF — malware analysis report

Static analysis result for SHA-256 a737db44568a2af8…

MALICIOUS

PDF

109.4 KB Created: 2021-03-15 10:45:20 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 557f33fcab39b2f75a0591d379289f1f SHA-1: e96c7ceb395c2748e1a940702b60d02f070be802 SHA-256: a737db44568a2af834e72ec9b77b523d1c1cf48be6fbac928fa704755a26874d
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, identified as a link farm, with a specific focus on terms like 'immunization exemption form'. The ML classifier and ClamAV detection strongly indicate maliciousness. The presence of embedded URLs and the nature of the link farm suggest this document is designed to redirect users to potentially malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://lozipotod.ru/123?utm_term=immunization+exemption+form+mn PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4464527/normal_600d2adb763d1.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369907/normal_5ff3ed8586faf.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4454161/normal_600350f97af90.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4469370/normal_600e051db299e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4410962/normal_604aa16e1ae36.pdfIn PDF document text
    • http://gosoxegekiri.mywebcommunity.org/bergeys_manual_of_determinative_bacteriology_latest_edition.pdfIn PDF document text
    • http://debegezuvume.iblogger.org/binigurewitotikariwoweka.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4387229/normal_600805475b390.pdfIn PDF document text
    • http://vebilodugisugod.iblogger.org/biochemistry_of_cell.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4378157/normal_6010dc4f52a10.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417523/normal_604d1fb0a8961.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4495841/normal_5ff3beb074c01.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382793/normal_601cf72f66df8.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://rewuwuja.onlinewebshop.net/acrobat_pro_reduce_file_size.pdfIn PDF document text
    • http://xanunomoz.rf.gd/breeam_international_new_construction_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ce8ddc3b-455e-4eff-affc-a413ff1ae86e/5965254193.pdfIn PDF document text
    • http://pifazudiso.rf.gd/casio_f-91w_watch_strap.pdfIn PDF document text
    • https://3a00e800-a8eb-44ae-aafc-ae9aecab8e06.filesusr.com/ugd/1715bf_206ed89cb6294c279ef350193b48694f.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/0f69fb59-b7de-4025-bf94-12f1cb7eda47/what_are_the_major_landforms_of_canada.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/087a7403-5d68-4487-b88b-538961c3e669/how_to_add_buttons_in_wix.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7b0a53c9-baf2-48df-bad1-a930ae06bfa3/sony_rx100_iii_price_australia.pdfIn PDF document text
    • https://02408c19-b9f6-4996-a596-1d5b7e46c8d3.filesusr.com/ugd/c83fdb_58f0b50993714907b0789074a45b2834.pdf?index=trueIn 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00016fb5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16FB5 4892 bytes
SHA-256: 365c168e7766813999627c0075cc756d91f52e6f4a4d000665993f6ac326d347
font_01_sfnt_off00018052.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18052 11904 bytes
SHA-256: ee518aa1bdc6246030479fbeca9a2aef2262e03944998496b288f66b5d866972