Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca88fff8a4467440…

MALICIOUS

PDF

95.1 KB Created: 2021-04-30 15:50:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f4b7ebc23426a1468948a4fa5234f13d SHA-1: 7b17d1a510930c550ae54c9351db5048a76207b6 SHA-256: ca88fff8a446744073d621039859630d4263480021b656bea05149d44796fb3a
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, identified by the PDF_SEO_LINK_FARM heuristic, suggesting a link farm or phishing attempt. The ML_NYX_PDF_MALICIOUS and ClamAV detections strongly indicate malicious intent. The embedded URLs, such as 'https://zajinet.ru/strik?utm_term=tempstar+central+air+conditioning+reviews', are likely used to redirect users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://zajinet.ru/strik?utm_term=tempstar+central+air+conditioning+reviews
    • https://cdn-cms.f-static.net/uploads/4391620/normal_603e74d0ad4e3.pdf
    • http://tojuvapemupo.mywebcommunity.org/manual_de_automatismo_industrial.pdf
    • https://static.s123-cdn-static.com/uploads/4484636/normal_5fe2518f33a49.pdf
    • https://cdn-cms.f-static.net/uploads/4450898/normal_6051b07fb4cca.pdf
    • https://static.s123-cdn-static.com/uploads/4426075/normal_5fe29fc8a2e7c.pdf
    • http://talobaniwi.iblogger.org/22698199776.pdf
    • https://cdn-cms.f-static.net/uploads/4385217/normal_60538dcb22a1e.pdf
    • https://cdn-cms.f-static.net/uploads/4414487/normal_6050b368d1f8f.pdf
    • http://safipewex.iblogger.org/89601784572.pdf
    • https://cdn-cms.f-static.net/uploads/4470218/normal_603ba86de1b46.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/kijelopazekune/jam_plus_2_speaker_pairing.pdf
    • https://s3.amazonaws.com/ziwuvijevo/pamavoxumexeraperise.pdf
    • https://eed7fa7e-4f31-4ba6-8269-e73f07ac74c5.filesusr.com/ugd/93374d_5101dcc76b99433f9852138806c08c9d.pdf?index=true
    • http://gutekuretejapoj.onlinewebshop.net/graph_paper_a4.pdf
    • https://7b4e975e-109f-4397-a679-93e438ff1453.filesusr.com/ugd/c33f71_1dab2534f70043ecacbc123411f4a070.pdf?index=true
    • https://s3.amazonaws.com/dapekufoxiraku/cheapest_best_trimmer.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013745.bin
3b321a8b6bc0e660a950f1172159f16b35cb4f6e86daa9f9a5e424a888694945
pdf-font-stream PDF embedded font (sfnt) at offset 0x13745 5492 bytes
font_01_sfnt_off000149eb.bin
62d6e060488b3ec1bd50ffbf7c60fcca8c92566c742b37cdc459f23cd8341a66
pdf-font-stream PDF embedded font (sfnt) at offset 0x149EB 11096 bytes