Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a43d05b3d8a6bd9…

MALICIOUS

PDF

81.6 KB Created: 2021-05-24 16:23:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 911f9b8510b00b34f9faeebcdae422a6 SHA-1: 3f130ec0d86d04430cc5ff56649e295845877836 SHA-256: 7a43d05b3d8a6bd9667fc3119a99a1af867d9b21277744d5f79a7f6f41b76611
186 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, containing numerous external URLs pointing to other PDF documents, likely to manipulate search engine results or distribute further malicious content. The presence of a `utm_term` parameter in one of the URLs suggests a tracking or redirection mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://leonvi.ru/strik?utm_term=matthias+schleiden+biografia+en+espa%25C3%25B1ol PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4463286/normal_5ff765c6380f6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416128/normal_601ff8c052954.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370304/normal_6032f5cb71abb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4373301/normal_60281e4874623.pdfIn PDF document text
    • https://pekavodasusoku.weebly.com/uploads/1/3/5/9/135982803/7997184.pdfIn PDF document text
    • https://nodeseverew.weebly.com/uploads/1/3/5/3/135323512/xepod-nepilogudazid.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446165/normal_600d7e4da3480.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450250/normal_5fd8223c1389e.pdfIn PDF document text
    • https://mulokigapasol.weebly.com/uploads/1/3/1/0/131070847/fitufavawoted.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4427267/normal_60152b019f7e9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403120/normal_5fe9e43de3618.pdfIn PDF document text
    • https://milalidit.weebly.com/uploads/1/3/1/4/131437162/jupidapusupu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/zabevog/4628872242.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ff5614c0-f3a0-427b-877a-4d62a14f962a/how_to_replace_the_handle_on_my_ge_microwave.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ab10aa90-3896-4e1e-8d6a-354e19850475/pathfinder_ultimate_equipment_paizo.pdfIn PDF document text
    • https://s3.amazonaws.com/busutafitufe/80470543318.pdfIn PDF document text
    • https://s3.amazonaws.com/gedesisumi/93348809777.pdfIn PDF document text
    • https://s3.amazonaws.com/woxewiwupir/cash_register_reconciliation_sheet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e7f96022-60e9-47eb-bf86-d04ed84a122b/serial_number_flip_professional_for_mac.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0d98b80c-eec6-4c31-80ab-049660f46215/42881560514.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/435f54df-baf9-486b-bd92-db1fcea58019/zanowugubekopegodetavoza.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2dca8316-7c12-4a2a-a9e0-17ad1ed9ab1c/niwelujamaluvefutozub.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/29eb936a-9c78-4670-a636-7271354e49c4/bus_simulator_indonesia_hack_game_apk_mod_android.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_off0000f7be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7BE 5776 bytes
SHA-256: 7e4836a0174e34ec5773d752b2aac9dbd7338251d972d94fa5681b1b3ff65018
font_01_sfnt_off00010b26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B26 13484 bytes
SHA-256: 3a23c26a0bfae4a31307762420144d87bc43f9267284519a4477ed24251ac37e