Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b3dad328b94c843…

MALICIOUS

PDF

79.8 KB Created: 2021-03-17 00:43:52 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: 48720bc539beefb8de23aa8d9eb30e91 SHA-1: f9ed779442aeaec0522a7faca3ed1f31a7b0aedc SHA-256: 2b3dad328b94c84375283c354bca76752dbe16da0140d9078cd6876397851083
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many hosted on disposable domains, suggesting a link farm or phishing operation. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, contains references to 'asvab prep app for android' and 'wkhtmltopdf', likely a lure to direct users to malicious URLs such as https://mezovuduw.ru/123?utm_term=asvab+prep+app+for+android.

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://mezovuduw.ru/123?utm_term=asvab+prep+app+for+android PDF link annotation
    • https://zaxifugerabapaz.weebly.com/uploads/1/3/1/0/131071175/fokexuximisowafa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459468/normal_6023f0af71b9a.pdfIn PDF document text
    • https://julavatevimire.weebly.com/uploads/1/3/4/6/134669339/mivegogomoxidupati.pdfIn PDF document text
    • https://sererewaxux.weebly.com/uploads/1/3/4/9/134903335/mikolupevil-nemav.pdfIn PDF document text
    • http://bionatur.space/gutter_guard_comparison_consumer_reports4zjv7.pdfIn PDF document text
    • http://vovality.club/vojunedovlmmuw.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387056/normal_603852e0e03b3.pdfIn PDF document text
    • http://airbin.top/honda_express_sr_for_salenbjh5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488139/normal_5fd95c9e89414.pdfIn PDF document text
    • http://igonlinesupport.com/lajirusafotimokuldjxe1.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://dekutob.epizy.com/business_proposal_letter_examples.pdfIn PDF document text
    • https://s3.amazonaws.com/kagedatabujo/65229453283.pdfIn PDF document text
    • https://ad0d0dbb-669b-46a9-85df-79487014a0f3.filesusr.com/ugd/00d95d_5df5b94fc4fe426384389825df789112.pdf?index=trueIn PDF document text
    • https://73856814-13bb-4d44-aeaf-752cce6ba6bd.filesusr.com/ugd/a0d21a_de1bc045dd564ec4aefc887da60cb650.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/vezumobigodub/functional_specification_template_confluence.pdfIn PDF document text
    • http://wubizojojepiso.epizy.com/midavofenosujevukawavage.pdfIn PDF document text
    • https://s3.amazonaws.com/megulu/durusanugatuj.pdfIn PDF document text
    • https://1bf92926-22d0-44a1-94fb-b51843c41cd5.filesusr.com/ugd/762c1a_8955af6fa82348b7a7cdc58bbec0f943.pdf?index=trueIn PDF document text
    • https://f07eb630-23ff-4298-a1df-d7940f1ba2dc.filesusr.com/ugd/097a5b_39c9dada5c3e469c905b4d852f04a3c8.pdf?index=trueIn PDF document text
    • https://0b609444-e5a2-4a7e-9779-a3c6bae51a53.filesusr.com/ugd/529dbf_d826a28513b043df88ac65d148a33341.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_off0000f721.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF721 5192 bytes
SHA-256: 4cf81501e341403fda4c8ac83a2ddbfcd7a7a8f58bf49c7f660d4612159ec91a
font_01_sfnt_off000108db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108DB 11540 bytes
SHA-256: 972d93bd933b6ca4e7170ddc3660a74b4006fb34b33e675feb7b204415f3ce4d