Malicious PDF — malware analysis report

Static analysis result for SHA-256 21fd35e357588d84…

MALICIOUS

PDF

96.6 KB Created: 2021-05-22 22:00:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-02
MD5: 044d0a166cc415db7b2cd37010c7ba74 SHA-1: 25d4b32dfa10ddea1e6c0e86883b3e5c41049540 SHA-256: 21fd35e357588d843443f890bd7cf5487ffa47b4a20f768751130641c936ffc7
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to disposable hosting, and is flagged by ML classifiers and ClamAV as malicious phishing content. The document body, though obfuscated, appears to present a fake error message to trick the user into clicking a link. The presence of external URIs and the link farm heuristic strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://fokemale.ru/strik?utm_term=io+error+java.net.socketexception+connection+reset PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4387807/normal_600f1152381a4.pdfIn PDF document text
    • https://kuvinobugo.weebly.com/uploads/1/3/1/3/131383931/vabijozonobe_kubudizukimiji.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4485929/normal_600164fc019e7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425217/normal_60525179db6c8.pdfIn PDF document text
    • https://tavifarexup.weebly.com/uploads/1/3/4/6/134611028/nelovele.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4450434/normal_5fe55580cf829.pdfIn PDF document text
    • https://baxovazexozubuv.weebly.com/uploads/1/3/4/3/134318553/parajosudipe-defim.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4376602/normal_5fcb6bbda1d3b.pdfIn PDF document text
    • https://bobilemako.weebly.com/uploads/1/3/4/7/134733435/mejumamuvaz.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485152/normal_6029add65acec.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4477864/normal_5ff5267f56b57.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4407313/normal_604ce72c15166.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4388814/normal_6008f1d3c17bc.pdfIn PDF document text
    • https://kidenido.weebly.com/uploads/1/3/1/6/131636891/miwalu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4424630/normal_5fd77d2351517.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
    • https://s3.amazonaws.com/sazixipame/lintelek_fitness_tracker_guide.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6359375d-7b26-4861-b4bd-afe4a27d160f/allworx_phone_manual_verge_9312.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9be9f9e1-63e5-4a5c-9e84-00a823809150/muresab.pdfIn PDF document text
    • https://s3.amazonaws.com/nakevoja/sidosedopumuwed.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2d31b7b3-3570-4000-9897-a9c9f4cbd0e2/16337364959.pdfIn PDF document text
    • https://s3.amazonaws.com/muvevanepen/how_to_do_a_military_contract_marriage_in_india.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2c4b6aad-4598-4a23-a538-02727326d92f/sentry_safe_open_code.pdfIn PDF document text
    • https://s3.amazonaws.com/zewimu/33278923876.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/deb092bf-5757-4bfb-aa6c-81233cd8d1ba/sesinuwunibegilolodul.pdfIn PDF document text
    • https://s3.amazonaws.com/dazifozixawus/instructions_on_how_to_use_kronos_time_clock.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00012c43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C43 4920 bytes
SHA-256: 93ba46a5dea9409dbfdbf652780d3078183b08fdc8f536d901078751ccd8e581
font_01_sfnt_off00013d19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D19 12040 bytes
SHA-256: 1f40f0b266fb610fb6945b0e115cf7d75a216a6e5f5c8514a8c49dad6dc98b36
font_02_sfnt_off00016628.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16628 4324 bytes
SHA-256: 9f355172d696dda274cac500966718f112ce76951f19577ac4888987ea6471b2