Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b9225a8eb95dd29…

MALICIOUS

PDF

74.6 KB Created: 2021-06-13 04:49:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: f4417b79d89f4c6a02b4fcc3a179aa5c SHA-1: cce6afaced5fd0e975fc907718cbf3057f4e1434 SHA-256: 8b9225a8eb95dd290c41c250d7d3e6356d9127aa6382b79fa1e7aedb53938c73
164 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by a ClamAV signature and an ML classifier. It contains numerous external links, with one heuristic specifically identifying a 'mass external PDF link farm'. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a URL that appears to be part of a link farm, suggesting an attempt to generate traffic or distribute further malicious content. The presence of embedded URLs and the overall structure strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://krisoc.ru/pbw?utm_term=zombie+horde+minecraft+server PDF link annotation
    • https://mixezefu.weebly.com/uploads/1/3/0/8/130874535/8680528.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4391623/normal_5fee996e66069.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387590/normal_605fb84d03fc1.pdfIn PDF document text
    • https://katigagu.weebly.com/uploads/1/3/4/7/134760011/namelifobagos-matimidejor-sugezes-wifexezoxat.pdfIn PDF document text
    • https://jarurozo.weebly.com/uploads/1/3/5/3/135320013/b937ae92.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/3b19d15b-e222-48f3-926c-8264606c5e5e/android_studio_device_offline_error_while_installing_apk.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/aa16848b-90a7-4469-bd1b-4703d83c5e2f/mikakijowusupewir.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/143c7ab2-8a88-497e-8405-0121b2b3a66c/samsung_s6_edge_instruction_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d414dcfd-637f-48cf-8321-9719ea9cbc49/electrical_wiring_symbols_and_meanings.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0c8fc94c-b62d-4f9a-8a83-2fffee324b9d/student_exploration_distance_time_graphs_answers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/89beaf74-71f4-44a6-bee9-c638053f9747/como_se_elabora_un_manual_de_organizacion_de_una_empresa.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8c0961f3-1155-471d-ab55-d3b85349156e/what_is_the_remote_code_for_sony_dvd_player.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/87cc05c0-0879-4110-a902-af1ecb117fb2/nogorogosidipi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/203d3664-e4ca-4b55-8e51-74f7f3548ac5/how_to_get_flint_and_steel_in_minecraft_survival.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6b195200-d061-461f-b903-4da455c4df3b/how_to_find_momentum_stocks_for_swing_trading.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ed67846e-415c-4634-97cb-a73d4bdb524c/57843351666.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/82f45b73-cb52-4edd-b3ec-25becb12ba3d/linesavutumupifivalapun.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/42365d74-87fb-4039-a6c9-8517b6c41d91/xajinodinasefi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d5a78777-6e87-469e-95d4-0bce6f8d147c/ford_mustang_gt_for_sale.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_off0000e43f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE43F 5388 bytes
SHA-256: 8e46a6fd70834667299d0e887677c3172f5c4910e4e456151971c5cb01a37b2d
font_01_sfnt_off0000f66a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF66A 11300 bytes
SHA-256: 997dc0ff23883c33f5a63e62f12aa31784646d7fe365bd27a048eb2b56c95ee9