Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5bd8d3c2b5629f9…

MALICIOUS

PDF

89.9 KB Created: 2021-04-07 01:18:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 7690eacea044d4cfa80caeca654de4c6 SHA-1: 28150f844ce9b3056ca510eebe038f7551774463 SHA-256: f5bd8d3c2b5629f93ade17bd0e52013d227f32e54a54c0c011c13c54375fedc9
154 Risk Score

Malware Insights

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

The PDF contains heuristics indicating it is malformed and contains external URIs, suggesting it is designed to redirect users. The presence of a 'download button' heuristic further supports a lure-based attack. While no scripts were explicitly extracted, the ML classifier and ClamAV detection strongly indicate malicious intent, likely involving the download of a second-stage payload from one of the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9920

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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.
  • 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://zajinet.ru/strik?utm_term=asus+rt-n66u+power+adapter PDF link annotation
    • http://visiblawty.com/rezirevuxorexeslhdj8.pdfIn PDF document text
    • http://mokenolovulonom.medianewsonline.com/allegiant_reading_studios.pdfIn PDF document text
    • http://avto-trokot.xyz/android_9._1_huawei_p_smart7prmv.pdfIn PDF document text
    • http://varnisvakq.ru/how_to_know_if_your_a_sun_moon_and_rising_sign6hrkp.pdfIn PDF document text
    • http://bukawavado.medianewsonline.com/tusufe.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4481819/normal_6008076d45f4c.pdfIn PDF document text
    • http://creditactive.info/tomefopewivl2ynd.pdfIn PDF document text
    • http://vasakuso.sportsontheweb.net/type_2_diabetes_mellitus_2020.pdfIn PDF document text
    • http://vopugixeroramox.medianewsonline.com/46963849392.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4405197/normal_602d0247a3a4d.pdfIn PDF document text
    • http://bitcoins-profits.com/bedobibaue13h.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4386852/normal_603a3e470e44a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369493/normal_602a5566d496f.pdfIn PDF document text
    • http://vejuwetuk.mypressonline.com/totexuxazukeliguranapevo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://204833c8-abda-4421-8777-5048ee7dd919.filesusr.com/ugd/e30b7a_a9f2375663234cc5b02d858a70a85bd1.pdf?index=trueIn PDF document text
    • http://ruronegiseko.atwebpages.com/66325924155.pdfIn PDF document text
    • http://palexibibiw.atwebpages.com/dadumawawenubulezojijus.pdfIn PDF document text
    • http://vefodipox.myartsonline.com/73367432879.pdfIn PDF document text
    • https://204833c8-abda-4421-8777-5048ee7dd919.filesusr.com/ugd/e30b7a_44279619c5794842b347d074a3c1d1f1.pdf?index=trueIn PDF document text
    • https://6e7ef639-f89a-4701-86f9-710a836f1183.filesusr.com/ugd/12745a_f0bfa1c13e9c4f309362cc6562990641.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/jalasilunaz/rojupukozonubukitukodu.pdfIn PDF document text
    • https://5e6d3f51-9b35-4a29-baf4-1f036254a461.filesusr.com/ugd/99a8f2_30930e4240734f42832f0ac7e56b0a13.pdf?index=trueIn PDF document text
    • http://fufudaloxola.onlinewebshop.net/muxisujageliwifuga.pdfIn PDF document text
    • https://s3.amazonaws.com/genedesowul/35098264746.pdfIn PDF document text
    • https://ad9e3d1f-bb22-46ca-892e-b6aa3325a756.filesusr.com/ugd/837d34_c9807c8934b7460080a31401d6e7e448.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/kakekojezutok/autoclave_user_manual.pdfIn PDF document text
    • https://s3.amazonaws.com/fedojigudaj/vewiruzusujiga.pdfIn PDF document text
    • https://s3.amazonaws.com/jezaxojipevu/gikiroxetuxozimexabusi.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
    • https://savannah.gnu.org/projects/freefont/In PDF document text
    • http://www.gnu.org/licenses/In PDF document text
    • http://www.gnu.org/copyleft/gpl.htmlIn 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fc5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC5C 6424 bytes
SHA-256: 50759c40df67ec181331d37bc16259f4db20c39507a2c7d18444f96545433770
font_01_sfnt_off00010c3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C3C 5188 bytes
SHA-256: 1712f97e9d0abce32ffeef0bbee777eebd1f02a7a816aeaf8b12ab63161fbdcd
font_02_sfnt_off00011e06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E06 11088 bytes
SHA-256: 7026615d3443b3acd238ccd440e0b486a66141f32a66333e8039473cf81e0882
font_03_sfnt_off000143e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x143E4 16208 bytes
SHA-256: 560e11d5da3ed60647d844d0127c34f4fbbc0b68999cbe35161ddcd790341c9f