Malicious PDF — malware analysis report

Static analysis result for SHA-256 a31f517d6a345331…

MALICIOUS

PDF

74.3 KB Created: 2021-06-05 18:41:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 79d95a1d1e78f65fb880bd82c46c84a3 SHA-1: 672e2d7f2699e548f7eb5f148e88f73fcfc5a06c SHA-256: a31f517d6a3453313cbb215efdd6f31ecd59f7fd296b6b49c334022c7f8abfed
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

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://laborke.ru/pbw?utm_term=fire+accident+report+writing+pdf PDF link annotation
    • https://matekulelesij.weebly.com/uploads/1/3/4/8/134858821/8791231.pdfIn PDF document text
    • https://gatimosuxanad.weebly.com/uploads/1/3/2/8/132814295/6245724.pdfIn PDF document text
    • https://xuratofojiwob.weebly.com/uploads/1/3/4/0/134096374/c4f5a7318411b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366965/normal_606bd8c215a5f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485318/normal_5fd8614d522dd.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4405946/normal_5fde6d5347184.pdfIn PDF document text
    • https://likuxosudiva.weebly.com/uploads/1/3/4/6/134603152/vevizozos_jewal_xeribisi_vizilulirig.pdfIn PDF document text
    • https://jemexegotida.weebly.com/uploads/1/3/4/4/134464186/bimojoger.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391602/normal_5fe6ef1b35034.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471969/normal_6028f9ed6ba68.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4496148/normal_603e618f43499.pdfIn PDF document text
    • https://judurufag.weebly.com/uploads/1/3/4/6/134688768/jofofafu.pdfIn PDF document text
    • https://famopenagunabot.weebly.com/uploads/1/3/4/6/134688774/4295523.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4486199/normal_5fd8dd136c197.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4477877/normal_5ffffefb60bec.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/6896d5b5-2795-4766-9f08-8ff270ed77ca/zejufitapemerimokasa.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/68aec90c-de45-4745-8dbf-c9873de196e3/what_is_the_molecular_shape_of_ch2o.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ea3c9ca0-2789-475d-a187-dee0f110f194/hidden_pictures_printables_thanksgiving.pdfIn PDF document text
    • http://malamojozag.pbworks.com/f/small_animal_adoption_near_me.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e5dfa3ce-8ba7-46fa-b3d6-7803c285e8dd/siwimijoxuturudo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fa3528a7-2537-4d6e-98f6-46f14dd208bd/43334044919.pdfIn PDF document text
    • http://sufizilofab.pbworks.com/f/how_to_fill_ink_in_hp_ink_tank_wireless_419.pdfIn 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_off0000e74a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE74A 5160 bytes
SHA-256: 5a62724e8e8400943aac71c2f47a12277ce16b3a2ea3965c1c41ca4cc346aca5
font_01_sfnt_off0000f903.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF903 10160 bytes
SHA-256: 5178a6b549870401c7e97c7e9a76fc560b7a92ff207b4c0a15a4dd0e7f818701