Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4cc2d4572904b72…

MALICIOUS

PDF

80.8 KB Created: 2021-03-12 18:31:38 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: f7357cd246eb0ed6fa55486af344173a SHA-1: 15c636210f5e161397dd477fdc081465b8d426c3 SHA-256: a4cc2d4572904b72ee9bbb12c523ddb90e1f5030a4429b57657252f24495b1a2
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many pointing to disposable hosting, suggesting a link farm used for SEO manipulation or phishing. The primary URL, https://kuzutuzo.ru/award?keyword=senior+system+administrator+job+description+pdf, further supports the lure of a job description to entice users to click through to potentially malicious 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
  • 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://kuzutuzo.ru/award?keyword=senior+system+administrator+job+description+pdf PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4416669/normal_6009262a0134d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368496/normal_6015b42f7e21e.pdfIn PDF document text
    • https://zowotojezef.weebly.com/uploads/1/3/4/3/134330732/tupelil-dudilufe-mebofexos-nawedunereneji.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415046/normal_6035a2346ef30.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4485689/normal_5fc91b71475db.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4485705/normal_5fc5eeee3d44e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447085/normal_5fdb55d7bc39e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4456985/normal_60140436693f5.pdfIn PDF document text
    • https://buketopol.weebly.com/uploads/1/3/4/0/134013372/selagowotonub_damagenizujitoz_tufaro.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4461232/normal_5fd21a12ae357.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425737/normal_5fd5fc62198fb.pdfIn PDF document text
    • https://vifegozotamideb.weebly.com/uploads/1/3/4/2/134236473/kexosesof.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/da5148d1-3161-43d3-9c0b-71c64e35fe05/vunofufibepobalita.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/31f30b29-1603-4820-8424-afb82ae6cfb1/schwinn_airdyne_ad4_windscreen.pdfIn PDF document text
    • https://79d86aa2-23c4-4aa0-a0dc-c16ac59ae55d.filesusr.com/ugd/ecb701_81c4ae37bdd04629873568d278a5b01d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/2138ac8b-673f-4d08-b7be-592e63873498/sense_and_sensibility_2008_soundtrack.pdfIn PDF document text
    • https://53ebb62d-ddaf-432f-8dc3-1f4746653467.filesusr.com/ugd/bbd3cf_e8e718b6bb894b99b978508951c033f2.pdf?index=trueIn PDF document text
    • https://dfa52777-3edb-460f-9b14-ca5101cd4ecc.filesusr.com/ugd/5360f8_bfcdec3cdc2a466eba6fe5a670d03f7b.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/b72b2592-ad29-4397-9098-72c880531db4/best_foods_to_eat_on_advocare_24_day_challenge.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5284ce03-a6f9-4a86-9280-774e5f45f7ac/nefopugekitunolo.pdfIn 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_off0000fd8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD8E 5688 bytes
SHA-256: c264083f223a0cbb125386e0725dabd1defe6078c29009ceeb119c25dc0dff05
font_01_sfnt_off000110dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110DC 10704 bytes
SHA-256: 405f6605b359283bf19835d346f621dc772cb2c76fce2b596005c7171bc45c99