Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4ef776ebdcd7cb3…

MALICIOUS

PDF

79.3 KB Created: 2021-04-26 18:56:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: bc4da9a22bfcf55bf445745af600dda7 SHA-1: d95ba85096dbfe679a9622d9cbce799194836ff9 SHA-256: c4ef776ebdcd7cb39aff743ec9ffa13be3d4bba834f4b9af8534134ce793b02e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

This PDF file was detected as malicious by ClamAV and ML classifiers, indicating a phishing or trojan distribution attempt. It contains a large number of external links, many pointing to PDF files, suggesting a link farm or redirection mechanism to host malicious content. The primary malicious URL identified is https://nipisod.ru/strik, which is likely used to serve a second-stage payload or redirect to a phishing site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://nipisod.ru/strik?utm_term=how+to+get+gerudo+outfit+age+of+calamity
    • https://xajimago.weebly.com/uploads/1/3/0/8/130813364/b1a2a0a96c.pdf
    • https://static.s123-cdn-static.com/uploads/4426814/normal_5ffcd18bd4028.pdf
    • https://cdn-cms.f-static.net/uploads/4427282/normal_5fe60a015b291.pdf
    • https://static.s123-cdn-static.com/uploads/4485705/normal_5ff96a8b106b1.pdf
    • https://cdn-cms.f-static.net/uploads/4369766/normal_605bba9f52be2.pdf
    • https://static.s123-cdn-static.com/uploads/4367310/normal_6006bd2d0714a.pdf
    • https://cdn-cms.f-static.net/uploads/4368756/normal_601ef349c09ca.pdf
    • https://static.s123-cdn-static.com/uploads/4376380/normal_5feb6134d8ad9.pdf
    • https://static.s123-cdn-static.com/uploads/4401694/normal_5fe3fb04ce4d5.pdf
    • https://cdn-cms.f-static.net/uploads/4379359/normal_5fe72f4922c0e.pdf
    • https://cdn-cms.f-static.net/uploads/4393761/normal_604a4e9667dec.pdf
    • https://cdn-cms.f-static.net/uploads/4408864/normal_60385883b374a.pdf
    • https://static.s123-cdn-static.com/uploads/4460981/normal_5ff41b3912a85.pdf
    • https://towizitubozabo.weebly.com/uploads/1/3/5/4/135400713/4192708.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://fb79ad55-22b5-4823-9538-35c71bbbd514.filesusr.com/ugd/ea423f_ce61db2b9f804785b162d04b59067697.pdf?index=true
    • https://8c0e102b-efba-4641-b7fc-347c26357927.filesusr.com/ugd/d420ee_5e3d25b30f0147b0a146ba9bdaaf27a3.pdf?index=true
    • https://21c505bb-01ca-4817-a549-4ed1ebba5040.filesusr.com/ugd/7d7105_2800750c37c74265b5ccabcc231a9a82.pdf?index=true
    • https://108bb973-5399-4bf7-a70e-a18780752cac.filesusr.com/ugd/760a88_2380ad89a34d48d6a338cd87be7be392.pdf?index=true
    • https://5c09c65f-4728-49e3-9562-8692e696fc4f.filesusr.com/ugd/32acb1_dc79581727f540edb310772753e5d961.pdf?index=true
    • https://adc67df4-9ac4-4169-8225-f8d60376216a.filesusr.com/ugd/a1c2c7_c5f6c8004d7046af9d2c261b5eb32ca1.pdf?index=true
    • https://ab737b70-891a-4a1f-8db9-ee548211cb31.filesusr.com/ugd/ce14f3_e6fc101adede4c1798867780ff0ea91d.pdf?index=true
    • 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_off0000f8b8.bin
0b9ffb9994ae59e26d608945a3f47ca775b2fd1127fb83eee7e0e1a636255848		 pdf-font-stream PDF embedded font (sfnt) at offset 0xF8B8 5320 bytes
font_01_sfnt_off00010ad9.bin
a2c8eca20fd1fec4770fc19cad40a873d1855d934dafa7e9463abb28576766ce		 pdf-font-stream PDF embedded font (sfnt) at offset 0x10AD9 10952 bytes

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