Malicious PDF — malware analysis report

Static analysis result for SHA-256 51ca3e468b4089d1…

MALICIOUS

PDF

87.2 KB Created: 2021-09-15 22:57:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 182911f22464968a46cc48fee3eb79f2 SHA-1: 7d49c625598ec7ba95976c1d4b20768e9ba20ad7 SHA-256: 51ca3e468b4089d1193e6613679cae9ee0b4dc21be802be3c04db711330cbbd4
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection for Pdf.Phishing.Trojan and an ML classifier indicating maliciousness. The presence of numerous external URIs, many hosted on disposable domains and utilizing UTM parameters, strongly suggests a phishing or malware distribution campaign. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure and heuristic firings point to a malicious intent to redirect users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 5

  • 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 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://synerhu.ru/uplcv?utm_term=iron+man+ppsspp+highly+compressed PDF link annotation
    • http://studioarchoggianiepartners.it/userfiles/files/loparaxu.pdfIn PDF document text
    • http://businesslegalgroup.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/veduwawume.pdfIn PDF document text
    • http://gsxr.hu/userfiles/file/39821549980.pdfIn PDF document text
    • http://zangerlelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/17705888586.pdfIn PDF document text
    • https://cailux.lu/userfiles/files/duwozadabuteberoz.pdfIn PDF document text
    • http://crystal-lamp.ru/uploads/files/21103598160.pdfIn PDF document text
    • https://www.fishhabitatnetwork.com.au/application/third_party/ckfinder/userfiles/files/jozojukonew.pdfIn PDF document text
    • https://em.heephong.org/ethnicminorities/cmsadmin/ckfinder/files/milalomobukokovat.pdfIn PDF document text
    • https://psychotherapie-coeppicus.ch/upload/file/lumogeme.pdfIn PDF document text
    • http://etyekilovarda.hu/userfiles/file/80526348029.pdfIn PDF document text
    • http://tekizolasyon.com/ckfinder/userfiles/files/jagiraru.pdfIn PDF document text
    • http://jyjjapan.jp/files/ckeditor/files/buzal.pdfIn PDF document text
    • https://jjcfurnituremaker.com/userfiles/files/3859349285.pdfIn PDF document text
    • http://lltsg.com/uploadfile/file///2021090909230596.pdfIn PDF document text
    • http://www.photonics-science.com/ckfinder/userfiles/files/38159154138.pdfIn PDF document text
    • https://jnnjhansi.com/userfiles/file/33947161978.pdfIn PDF document text
    • https://www.indoorclub-informa.com/boletines/img/file/21591175210.pdfIn PDF document text
    • https://ardiinerkh.mn/uploads/userfiles/files/20678038577.pdfIn PDF document text
    • http://mydreamtuscanwedding.com/editor_up/96088230640.pdfIn PDF document text
    • http://pickup-ws.com/userfiles/files/27146135502.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1614082c96672c---fomonozaxisizagiputo.pdfIn PDF document text
    • https://jewfri.kr/files/image/files/9232830976.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_off0000ebf4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBF4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001040b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1040B 10928 bytes
SHA-256: 624cd735012916f08bce17b2102f3c237853fec322db5552cc4dea9ac70b8afa
font_02_sfnt_off00011ce9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CE9 19008 bytes
SHA-256: f5f502b31da8878f0208143a49866da42de382be3c1e664a8dd056aadfd3ed07