Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd71b3183f35472e…

MALICIOUS

PDF

78.1 KB Created: 2021-03-11 17:44:36 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-31
MD5: bfa24c9ced71627a3758091e084681ef SHA-1: 922dfb93be93b943e8227e373c39d8c9d4d3aa06 SHA-256: cd71b3183f35472e4c3d463bcd7dc2672b18d62bcfeb89acd44fa02b3711d370
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to other PDF documents hosted on disposable domains, indicative of a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution via these links. No scripts were extracted, but the sheer volume of external links and the heuristic firings point towards a malicious document designed to lure users to external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://vilenefex.ru/123?utm_term=center+of+excellence+smartsheet PDF link annotation
    • http://bidimiw.sportsontheweb.net/rogukefudazoj.pdfIn PDF document text
    • https://nibafokabatawal.weebly.com/uploads/1/3/0/9/130970001/jivip.pdfIn PDF document text
    • https://cdn.sqhk.co/kuxaroposa/haM1Wgh/bipusavomutoxubidub.pdfIn PDF document text
    • http://tuvivukaroj.mygamesonline.org/communist_manifesto_definition_world_history.pdfIn PDF document text
    • https://cdn.sqhk.co/zoribakim/jiatagc/95752729618.pdfIn PDF document text
    • http://kismykeitio.best/un_curso_de_milagros_audiolibro4wqmf.pdfIn PDF document text
    • https://lugifepitel.weebly.com/uploads/1/3/2/7/132710690/zalazokimokaxise.pdfIn PDF document text
    • http://beststudent.space/85793432454cmt5h.pdfIn PDF document text
    • https://sazoxizifa.weebly.com/uploads/1/3/4/5/134505384/xemagasilex-nozoxogek.pdfIn PDF document text
    • https://wisolowiguwo.weebly.com/uploads/1/3/4/6/134630140/7cd367.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://29ca30ec-7ad4-487f-8637-d2d67f3a323c.filesusr.com/ugd/10b11f_c100611fb6a2455d83c59c804d7000e3.pdf?index=trueIn PDF document text
    • https://4c72699b-aa2e-4dc8-8bd5-1a54e8f938a6.filesusr.com/ugd/f3cb45_daf9428d19a240f4aee59314a71e4810.pdf?index=trueIn PDF document text
    • https://2eb5e741-fe40-4e13-9a70-20af0821b154.filesusr.com/ugd/6cf56c_8f88cb83f3e14923ac5c2305cede4537.pdf?index=trueIn PDF document text
    • https://a815f367-2516-4b88-9496-eed07d5c1eb7.filesusr.com/ugd/665c20_211f79e284e84fae83f574f127021c08.pdf?index=trueIn PDF document text
    • https://7be326e9-a1fd-4761-a84c-83c904220737.filesusr.com/ugd/37e945_854d02b09245485aa6844011e01c3579.pdf?index=trueIn PDF document text
    • https://ec2d952e-5494-46d8-b841-fee222248b17.filesusr.com/ugd/9713d5_33397b9a29e344d680536d9f06069207.pdf?index=trueIn PDF document text
    • https://f6ce3cfb-f922-470c-9e0e-eaf724001b0e.filesusr.com/ugd/defcb2_0006e0952b274766b804c946a985bc09.pdf?index=trueIn PDF document text
    • https://32b33340-d9da-4ef7-b3bd-a0ac5134eb71.filesusr.com/ugd/adfa6f_5402e44b57474dda8ca982f6ad3b4464.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e6cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6CF 4952 bytes
SHA-256: 38d99296d6478a79f03621d0daf2ac53923a4800bf900bd694af16946d08e05d
font_01_sfnt_off0000f776.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF776 11108 bytes
SHA-256: ad1179c58de6fbf5a30d10054d10dbd44e24caba06c3b725f4a82842ef940464
font_02_sfnt_off00011d27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D27 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378