Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf1e6d3d158ba465…

MALICIOUS

PDF

68.8 KB Created: 2021-09-18 05:10:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: dc7e133e4d0be46ccb47d5903386f667 SHA-1: ab14479175f8cbc5d233576bc161a676c7ee15a8 SHA-256: bf1e6d3d158ba465e716c160d7694507694358b006b8df9f03f81939bd3cc4c9
146 Risk Score

Malware Insights

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

The PDF file exhibits characteristics of a malicious document, including malformed streams and a high ML classifier score. It contains a large number of embedded URLs pointing to various domains, suggesting a phishing or malware distribution attempt. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports its malicious nature. No scripts were extracted, but the numerous external links are the primary indicators of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9962

Heuristics 6

  • 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.
  • 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://cructi.ru/uplcv?utm_term=borderlands+3+local+co+op+pc PDF link annotation
    • https://kaowei.tw/image/files/20210903_011855.pdfIn PDF document text
    • http://detskaoptika.cz/ckfinder/userfiles/files/gafek.pdfIn PDF document text
    • http://beijingxinzhi.com/userfiles/file/20210916060532_2050264189.pdfIn PDF document text
    • http://universalthailand.com/images/uploads/ckfinder/files/lubaxasugizuwatobapegelo.pdfIn PDF document text
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141c140eb4d8---77413886818.pdfIn PDF document text
    • http://skomi.ru/img/files/file/68717547434.pdfIn PDF document text
    • https://oreopay58.com/ckfinder/userfiles/files/34637238835.pdfIn PDF document text
    • https://www.dogandemir.av.tr/paketler/ckfinder/dosyalar/files/xuxunakoligeruxemesutif.pdfIn PDF document text
    • http://uni-soar.com/userfiles/file/49868929317.pdfIn PDF document text
    • http://prograsifkalip.com/files/dugimetamenije.pdfIn PDF document text
    • http://tysons-cafe.com/uploads/files/30391155329.pdfIn PDF document text
    • https://kalashad.com/userfiles/file/50623273168.pdfIn PDF document text
    • https://dichvumayphoto.vn/webroot/img/files/73685370046.pdfIn PDF document text
    • https://shen-su.eu/gfx/userfiles/files/zelegugojetibabubujex.pdfIn PDF document text
    • http://koddous.com/userfiles/file/fegojipalugumunerako.pdfIn PDF document text
    • http://yokohama-model.com/userfiles/files/94006480542.pdfIn PDF document text
    • http://infrabud.eu/fckpliki/file/nusabujozaxebiwog.pdfIn PDF document text
    • http://bielle-srl.com/userfiles/files/siritalaviredovini.pdfIn PDF document text
    • https://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/4b9760736244bd2884f3ccfbd379358f/kurikiludagaseboguxujideb.pdfIn PDF document text
    • http://lawyermo.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sezosagosaxolifuju.pdfIn PDF document text
    • https://eurochen.com/UpFiles/WebEditorFiles/file/16683671263.pdfIn PDF document text
    • https://samngaimarble.com/html_upload/file/8732946709.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://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_off0000afce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFCE 15064 bytes
SHA-256: f905382ef4e9a78a94ace095dcb0d2bfe9437ca3f516bbae13be0400a276ec18
font_01_sfnt_off0000d5e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5E7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000edfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDFE 10544 bytes
SHA-256: 5820c7e75f8adf5c1cd0d2ef62c0cfc8e08b9574e5c2f34b77cfaa7f84b578a5