Malicious PDF — malware analysis report

Static analysis result for SHA-256 5e74c314d854b0dd…

MALICIOUS

PDF

73.9 KB Created: 2021-02-27 20:45:48 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 24db4e11d70e3bb723013eb78879100c SHA-1: 0b9bc479ac4bce400f11c5d557bdf1a563b434a5 SHA-256: 5e74c314d854b0dd0a5c8dde227c3dfe603adc2be73051a1854c3282c9815cfa
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, identified as a link farm by heuristics. ClamAV and ML classifiers also flagged this file as malicious, specifically as a phishing trojan. The primary attack pattern involves directing users to a network of other PDF documents, likely for malicious redirection or SEO abuse.

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://soxebez.ru/wix?keyword=ventajas+y+desventajas+de+la+quimica+organica
    • http://3203epworthcres.com/batirug15zp.pdf
    • https://static.s123-cdn-static.com/uploads/4385421/normal_600356e0acb4d.pdf
    • https://static.s123-cdn-static.com/uploads/4373788/normal_5ff442a28d7b1.pdf
    • https://cdn-cms.f-static.net/uploads/4426270/normal_60310052c8d72.pdf
    • https://cdn-cms.f-static.net/uploads/4403820/normal_601e843dbe67f.pdf
    • https://cdn-cms.f-static.net/uploads/4420761/normal_602ff302756e2.pdf
    • https://nefopenexa.weebly.com/uploads/1/3/0/7/130739549/xerapitokerel.pdf
    • https://xududegugi.weebly.com/uploads/1/3/1/6/131636960/e8b1c06.pdf
    • https://kokarino.weebly.com/uploads/1/3/5/2/135299240/vowixubosokejiweteg.pdf
    • https://kelesidudukakub.weebly.com/uploads/1/3/5/3/135340861/4909594.pdf
    • http://how2clever.com/sekorekoberenapam6jc93.pdf
    • https://cdn-cms.f-static.net/uploads/4486984/normal_600b140a596ac.pdf
    • http://keysecret.ru/is_parallel_parking_on_the_driving_test_in_ga0y81m.pdf
    • https://javekekowunafot.weebly.com/uploads/1/3/5/3/135324960/bamulal.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • 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_off0000dfd0.bin
c851a9eff356497954cdcb7760d96d3ca5542f759d0f410bfbf59aeeaff50e96
pdf-font-stream PDF embedded font (sfnt) at offset 0xDFD0 5588 bytes
font_01_sfnt_off0000f2cb.bin
6082ac28390fe5a8f57ba3438054864f0e8fad4ccfe98b66f6a729cd541028aa
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2CB 11764 bytes