Malicious PDF — malware analysis report

Static analysis result for SHA-256 507b9e7d53b3c190…

MALICIOUS

PDF

75.0 KB Created: 2021-03-12 20:46:18 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-17
MD5: bb612811bc3fdcc6a026847b65fc10a3 SHA-1: 0238423b87c1fef9d6475d07f1854f066d79296a SHA-256: 507b9e7d53b3c190464caab3d25dd3ba76d57207f24ffea730edc477f7aaabe8
186 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains numerous external links, many pointing to disposable hosting, and one primary malicious URL disguised as an OSHA construction safety manual. This suggests a phishing or scam attempt to redirect users to a potentially harmful site.

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://soxebez.ru/strik?utm_term=osha+construction+safety+manual PDF link annotation
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://4cf6c2b4-cd84-4b73-83b1-bf7f441162b2.filesusr.com/ugd/e50c99_1072f8480fee44a7a7723958e21e40c9.pdf?index=trueIn PDF document text
    • https://f06ae689-34e6-4fd9-b749-a5985747e370.filesusr.com/ugd/4117a9_d00eb7c231de439382218c16086afcc0.pdf?index=trueIn PDF document text
    • https://5b0e1d79-1acc-45ba-a965-31015372eee8.filesusr.com/ugd/67f5f7_acff8cb5f0a64c5f8a7973d98c0fb1d7.pdf?index=trueIn PDF document text
    • https://5a11eff3-0c7a-45dd-bb89-060d4d4d2060.filesusr.com/ugd/72216b_7024ad54344d42409d5f9883dd1c14ce.pdf?index=trueIn PDF document text
    • https://3485775d-af35-4505-8fb4-f6750f575e04.filesusr.com/ugd/42f18e_df644d1132574eb9bae7ad463418ac5a.pdf?index=trueIn PDF document text
    • https://e082cb0d-9c22-4a21-acb7-e2c6127a51d3.filesusr.com/ugd/ff0c06_09d56c4938a94f23a1831bf8db51f308.pdf?index=trueIn PDF document text
    • https://48bd7725-9370-4d18-884e-e75d7b70c9c4.filesusr.com/ugd/f241d9_7a3f6c7afb6247d486335d1e95ce546b.pdf?index=trueIn PDF document text
    • https://d4f1f58f-bd44-402a-a4b0-a3aa01e36dbf.filesusr.com/ugd/dffefa_41ac1f0f4ff449658c4c0c1f9764ecc9.pdf?index=trueIn PDF document text
    • https://df1882fa-13c5-42f1-8438-577935b594b9.filesusr.com/ugd/91932b_63f3ca4c53f34439bccae9d07bce7c50.pdf?index=trueIn PDF document text
    • https://28ae28a3-27cc-4d38-be83-0de1f6925f83.filesusr.com/ugd/454016_06e5f602de664f3797e006e8cb563547.pdf?index=trueIn PDF document text
    • https://229013d5-0e14-4531-be8c-43df84542e77.filesusr.com/ugd/e4a895_de5e7f7b76eb4353b1cbd22f608d0c4b.pdf?index=trueIn PDF document text
    • https://c7972686-9310-4d97-8ac3-15e828887225.filesusr.com/ugd/8a419d_79c7819d49d2413c9f8a14bed9193e98.pdf?index=trueIn PDF document text
    • https://6ec3981f-6443-463b-a164-91fc69f101d9.filesusr.com/ugd/7603ae_a45caeaf067a4cd1ab4feb1066a399ad.pdf?index=trueIn PDF document text
    • https://46d16763-6c5f-4e19-aa2c-3f4071fcbec2.filesusr.com/ugd/26f730_0a01be1a1a3f4ee5830acf441a9ff073.pdf?index=trueIn PDF document text
    • https://8b8c7005-3af0-45a1-8e5b-a6902caa9335.filesusr.com/ugd/dbd7d9_0e893ca5fbbf48c0a04c4b26133eb925.pdf?index=trueIn PDF document text
    • https://ec679cc6-872a-45a8-b2fd-b1bc8f6ddb77.filesusr.com/ugd/d1d005_bd62eb49a72446208c230e3daf302638.pdf?index=trueIn PDF document text
    • https://0e8f88b9-656e-4b05-9cd8-8bd477f85547.filesusr.com/ugd/95b9ea_4360e582ec084466a69f54bcc0236e95.pdf?index=trueIn PDF document text
    • https://1f2f8e77-98df-4c5e-b88a-83bc2b612b58.filesusr.com/ugd/5c7528_74f2f321d5c641c0bd322db4fd69f247.pdf?index=trueIn PDF document text
    • https://8fa10226-37c2-454d-bd65-ced70ecbf0c4.filesusr.com/ugd/c34aa9_10921ce4f72d4a7d9a1b1d710476ba03.pdf?index=trueIn PDF document text
    • https://5e1ecd50-e572-447e-9dd1-c60ce64867c5.filesusr.com/ugd/9b2d9b_facd68f4f6f14718986f13e8233a5c14.pdf?index=trueIn PDF document text
    • https://09ec9d85-9312-4337-94d0-b84080e05f2e.filesusr.com/ugd/ac0094_bb7047a6b1e242a8a7f614cec5d017a7.pdf?index=trueIn PDF document text
    • https://ce55c564-0e79-48ac-bd91-a034cff8554b.filesusr.com/ugd/bd1fc0_65b60a26c49c49ed8713ed14ec9f8061.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_off0000e939.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE939 5248 bytes
SHA-256: 8628a633249bad684a0d1586fa12b6f8ea42a988e0397601589ce90343fbc933
font_01_sfnt_off0000faed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAED 10504 bytes
SHA-256: f34d2fd9eb7490db83b4fbd2ac537c68b54c937416c9d3bbd6c2f92c9af63e36