Malicious PDF — malware analysis report

Static analysis result for SHA-256 85872f76d2264903…

MALICIOUS

PDF

76.0 KB Created: 2021-06-06 05:09:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: b4f9d7f3ca86f1d11f3368fafd7bbf1f SHA-1: 23ceee1a96d7877073978e01435893aede96af98 SHA-256: 85872f76d2264903fabe94d2931a3a407b701f82e35abb66e98a2b5dfd161764
194 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, many pointing to disposable hosting services, characteristic of a link farm designed to obscure malicious activity. The ML classifier and ClamAV detection strongly indicate malicious content, likely a phishing or trojan payload delivered via these links. The presence of a 'download button' heuristic further supports a lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://krisoc.ru/pbw?utm_term=pirates+of+the+caribbean+song+piano+sheet+music PDF link annotation
    • https://guvizetajujuwu.weebly.com/uploads/1/3/4/6/134617183/2785047.pdfIn PDF document text
    • https://nebegozanukasaz.weebly.com/uploads/1/3/4/6/134699913/dopuj_zomozaxamobam.pdfIn PDF document text
    • https://rulodewarozuw.weebly.com/uploads/1/3/4/6/134678260/5de2c1b31b9c0e.pdfIn PDF document text
    • https://walagikolisof.weebly.com/uploads/1/3/4/4/134494282/piwomikakisabe-xuduk.pdfIn PDF document text
    • https://zedodunojoponex.weebly.com/uploads/1/3/6/0/136083391/kogajekofurugosewik.pdfIn PDF document text
    • https://nabezaxe.weebly.com/uploads/1/3/4/8/134852032/somumavuzox_xilemadevanawa_nupoferagox.pdfIn PDF document text
    • https://poriveba.weebly.com/uploads/1/3/4/3/134316211/pusisadigomadibuveb.pdfIn PDF document text
    • https://luxisawevevolal.weebly.com/uploads/1/3/2/6/132682936/soxibenu.pdfIn PDF document text
    • https://molilavavabofu.weebly.com/uploads/1/3/5/9/135989114/mutopepetipabus_rurum.pdfIn PDF document text
    • https://rajarajo.weebly.com/uploads/1/3/1/3/131398110/5828aae834.pdfIn PDF document text
    • https://wovodolu.weebly.com/uploads/1/3/4/8/134861979/jamuduxuwegaja-kesuku-sowowode.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://zikasamu.pbworks.com/f/10661150162.pdfIn PDF document text
    • http://molosafokaji.pbworks.com/f/avengers_theme_trombone_quartet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7e8e5102-98b7-414f-8854-4794e6819cc9/g-shock_mini_4706_manual.pdfIn PDF document text
    • http://gufabewa.pbworks.com/f/spotify_premium_free_apk_ios_2020.pdfIn PDF document text
    • http://fevawigo.pbworks.com/w/file/fetch/144420654/lebukixarederewo.pdfIn PDF document text
    • http://gediripu.pbworks.com/w/file/fetch/144557622/26985118642.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0f5d920f-8822-498b-adaa-4b2d92be020e/vosafibitivikuvezabisi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7da26c13-7f50-42ea-bab1-d1e930472c2c/100_verbos_irregulares_mas_usados_en_ingles.pdfIn PDF document text
    • http://dibesusajob.pbworks.com/w/file/fetch/144440751/cual_es_el_origen_de_la_fabula.pdfIn PDF document text
    • http://nozobitativi.pbworks.com/f/42485705418.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_off0000e9a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9A5 5540 bytes
SHA-256: c10d7f8008e86cdeab5ea44530eec7651e23ad3f06fa70ce2070c7231f3a0230
font_01_sfnt_off0000fc54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC54 11128 bytes
SHA-256: d4c3c5c1de403948366cf80af200da32d117922db8402f9211000cbc44cc6007