Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4d8a25f6131a8e9…

MALICIOUS

PDF

75.5 KB Created: 2021-03-25 16:59:26 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 271a5065cad9c7e686d0929e363143d1 SHA-1: 6506ce3a2b551f17da16fc7728606e8dc644db59 SHA-256: d4d8a25f6131a8e9fcdc8e429e2fc5292be77a784491ca75d27fa918be565021
156 Risk Score

Malware Insights

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

The PDF contains heuristics indicating it is part of a link farm and is flagged as malicious by ML classifiers and ClamAV. It embeds an external URI pointing to 'soxebez.ru', which is likely the primary malicious destination. The document body, though heavily obfuscated, contains references to a Tascam audio recorder, suggesting a lure to disguise the malicious intent. No scripts were extracted, but the PDF structure and embedded URLs strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://soxebez.ru/strik?utm_term=tascam+dr-05+stereo+portable+digital+audio+recorder
    • https://cdn-cms.f-static.net/uploads/4455376/normal_6058d73d3f1cb.pdf
    • https://static.s123-cdn-static.com/uploads/4417403/normal_5fee619b8bccd.pdf
    • https://static.s123-cdn-static.com/uploads/4422368/normal_5fe40412d51ca.pdf
    • https://static.s123-cdn-static.com/uploads/4392861/normal_5fef0d45d0e95.pdf
    • https://fipokotosa.weebly.com/uploads/1/3/4/5/134506619/gekeloxifebavoroziko.pdf
    • https://static.s123-cdn-static.com/uploads/4495531/normal_5fe5b23f872eb.pdf
    • https://cdn-cms.f-static.net/uploads/4472204/normal_602407b10bab0.pdf
    • https://cdn-cms.f-static.net/uploads/4443337/normal_5fd68516c05a8.pdf
    • https://static.s123-cdn-static.com/uploads/4463532/normal_5ff1ff70eeea1.pdf
    • https://cdn-cms.f-static.net/uploads/4492245/normal_60294b6f3baa6.pdf
    • https://static.s123-cdn-static.com/uploads/4418973/normal_5ffc697ba3730.pdf
    • https://cdn-cms.f-static.net/uploads/4374198/normal_602bff2edcfba.pdf
    • https://static.s123-cdn-static.com/uploads/4368759/normal_600316b84c8e3.pdf
    • https://wirolarem.weebly.com/uploads/1/3/1/6/131636642/pinujafili.pdf
    • https://static.s123-cdn-static.com/uploads/4498345/normal_5fc8723c7b03f.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/jolituzoji/37210976663.pdf
    • https://uploads.strikinglycdn.com/files/a889399d-a7b9-4d5f-89d2-03414118de6b/how_to_study_for_ccs_cases_step_3.pdf
    • https://s3.amazonaws.com/nisiwanolom/pert_chart_critical_path_template.pdf
    • https://uploads.strikinglycdn.com/files/1ad3f049-0fff-4d46-adc1-a6ab4ed915c5/how_much_is_a_netherland_dwarf_rabbit_eat.pdf
    • https://s3.amazonaws.com/sowewazulejewi/forbidden_archeology.pdf
    • https://s3.amazonaws.com/vosimalume/data_science_degree_texas_am.pdf
    • https://s3.amazonaws.com/kugelilizibuwum/77474183563.pdf
    • https://uploads.strikinglycdn.com/files/80604c87-391b-4898-89e3-446d3665e60d/65111894176.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_off0000e6cb.bin
6e7a862508aa9228df32d5120a4039ff98b5b88bbb8ef6c8c5f421f195008573
pdf-font-stream PDF embedded font (sfnt) at offset 0xE6CB 5780 bytes
font_01_sfnt_off0000fa59.bin
bdb4a5e3c8d052d44821ce56697b86b6da41fe26073d54c1d3f4d9074986d68f
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA59 11600 bytes