Malicious PDF — malware analysis report

Static analysis result for SHA-256 f81ba0e087ee270b…

MALICIOUS

PDF

77.9 KB Created: 2021-03-23 11:11:44 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: cd088b234f8d54292d70938221fda5d4 SHA-1: 75e19eaee8bfe1372c5cf8400d4f72d10b5905ec SHA-256: f81ba0e087ee270bdeec331acd17b66cf1593b3a0688586de7ee3d6a668dbe19
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm or phishing operation. The document body, though heavily obfuscated, appears to be a lure related to educational content, likely to trick users into visiting the malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://bologen.ru/123?utm_term=chloroplast+and+mitochondria+worksheet+answers+figure+1 PDF link annotation
    • https://xutonipojoneri.weebly.com/uploads/1/3/4/6/134667901/vubilomir_sibaz.pdfIn PDF document text
    • http://resokipuga.getenjoyment.net/aes_algorithm_tutorial.pdfIn PDF document text
    • http://lotukaguw.sportsontheweb.net/augusto_monterroso_mister_taylor.pdfIn PDF document text
    • http://medebupima.sportsontheweb.net/chen_linear_system_theory_and_design_solution_manual.pdfIn PDF document text
    • https://rojogibolodo.weebly.com/uploads/1/3/0/7/130775817/1310450.pdfIn PDF document text
    • https://feronokemafa.weebly.com/uploads/1/3/1/1/131164109/nejidumigore-xinom.pdfIn PDF document text
    • https://gibuximo.weebly.com/uploads/1/3/4/6/134665594/muzemediviniv.pdfIn PDF document text
    • https://memezuwiz.weebly.com/uploads/1/3/4/7/134702577/9130106.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://d926c97b-7f3b-4ec8-a52a-318bcb589338.filesusr.com/ugd/120f26_68f30eb838f1411781586cc45216cce8.pdf?index=trueIn PDF document text
    • https://6baea7ca-81e4-4a11-8410-716433a99462.filesusr.com/ugd/764aaa_942998332e794bac9639589adce71623.pdf?index=trueIn PDF document text
    • https://32e47638-7206-44c1-ad53-5c6f9176402e.filesusr.com/ugd/e00742_f79ca3c1150042e3a9918f6a0e37ec34.pdf?index=trueIn PDF document text
    • http://nuzikenevizut.onlinewebshop.net/nuvuwiwezem.pdfIn PDF document text
    • http://xijidejejinenoz.rf.gd/bowarifasibudi.pdfIn PDF document text
    • http://judewal.rf.gd/commonlit_herd_behavior_answers.pdfIn PDF document text
    • https://45dcde1a-aed5-4138-b95e-a0f768a283bf.filesusr.com/ugd/89441e_2af655554f5241fa88953e8e8a3af0a7.pdf?index=trueIn PDF document text
    • https://b54663a3-ff9d-4122-b75c-69b71428c9b0.filesusr.com/ugd/cfa91a_f23b978f3ed84130a9b5838129b1caaa.pdf?index=trueIn PDF document text
    • https://3c86e5df-9a55-47dd-9d5b-c207b25ec6cd.filesusr.com/ugd/72bf36_d532009132714dda96e1697fb055e80c.pdf?index=trueIn PDF document text
    • https://a7da3e60-63c8-46c1-a846-eab7df628ed2.filesusr.com/ugd/bba345_41af2ee74e7e40c4a8add8a122fb3449.pdf?index=trueIn PDF document text
    • http://puvapulugo.onlinewebshop.net/dafiguledonanepunoja.pdfIn PDF document text
    • https://80172413-d145-4b71-b7cf-4a007d76ad29.filesusr.com/ugd/cacfd7_511b4b51dbd246b590d2db5ad2c3971d.pdf?index=trueIn PDF document text
    • https://6baea7ca-81e4-4a11-8410-716433a99462.filesusr.com/ugd/764aaa_060d7d1333194999bcafc7ab9a399346.pdf?index=trueIn 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f0b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0B3 5680 bytes
SHA-256: 0fd5d52a0122ed8d3e7e4aaf7dc7971b8984454d225aec0db9cb4c2ef8985882
font_01_sfnt_off000103ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103EE 10416 bytes
SHA-256: e190c6c691b7ab32586c6f1d02e0060fbc8520a3e4598a9c7b59252c47185cd8