Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8290808f0a4ec72…

MALICIOUS

PDF

80.9 KB Created: 2021-05-29 22:06:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 1883042920f93d10ed2a455cb6a577ea SHA-1: c9f52ecc00dbdedd2484777b5e04a1c9d27558f5 SHA-256: d8290808f0a4ec722c923ee1fb20b2e43df28407fd3128fd9769a930d96c10f7
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing or malware distribution attempt. The heuristic 'PDF_SEO_LINK_FARM' suggests the document contains numerous external links, with one pointing to 'https://nipisod.ru/123?utm_term=inspection+report+software'. The document body, though heavily obfuscated, contains strings related to 'wkhtmltopdf' and 'inspection report software', reinforcing the lure. No scripts were extracted, but the presence of external links and the malicious verdict strongly suggest a phishing or downloader attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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.
  • 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://nipisod.ru/123?utm_term=inspection+report+software PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4388173/normal_5fcd863f408c2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368218/normal_5fd2590d1faa8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369796/normal_5ff98cbc3a02d.pdfIn PDF document text
    • https://bepizapumi.weebly.com/uploads/1/3/5/3/135349865/mokonofe-zamiw.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4444622/normal_6032525e9e9b8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391903/normal_604ca6f031b38.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4377935/normal_60475471c0ece.pdfIn PDF document text
    • https://xizotikozuza.weebly.com/uploads/1/3/4/5/134587863/kawesoriv.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4381083/normal_605d69dbb6e23.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4414688/normal_5fcef592ceb38.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376404/normal_6050c7c4118c2.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/b3f5fab8-e432-4973-a272-ebe7817c4239/begedurapumubope.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/29b22685-5602-45e5-bc31-71272dd99da3/farmville_2_hack_cheat_tool.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4d9061d6-2dad-4146-a98e-2db731ebad3f/enteral_vs_parenteral_drug_administration.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c646d5ea-68b4-42de-8b20-d9049446ec64/11003349568.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7042a5ed-1011-4318-b36f-bb3c53a45c2a/how_to_formulate_survey_questionnaire.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1e763c80-de88-41b7-ad37-d1ccc0f20684/sojizuvekugazanejiseb.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/42c48be6-6ec8-4752-a8af-e8de7503ffe4/56947242909.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e564f914-e318-40fb-a6bf-1eac8e423dc3/how_many_carbs_are_in_a_regular_arbys_roast_beef_sandwich.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7b63e997-9996-42d2-9b70-15cbc88d3397/how_to_heat_a_house_with_wood_stove.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/189848ae-c97f-49c8-bfed-0a021680eeae/penny_stocks_to_buy_2020_reddit.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e8fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8FB 5004 bytes
SHA-256: ef7f3eee76c086433921567357af7ec2e647e69691096927f2a21789abbcd25b
font_01_sfnt_off0000fa21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA21 11040 bytes
SHA-256: b1d299d32a52477b942b4d353b0a83d008363040ae39f7ce03a508f2bb103b88
font_02_sfnt_off00011fa6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FA6 16544 bytes
SHA-256: 49230a07578f2a0b108554ff1d47b1cb24b8f8081254bad551c0ce72ea05e0a5