Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1171f2d356fcd99…

MALICIOUS

PDF

71.8 KB Created: 2021-09-13 17:34:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: dc33d43b0f4d0ba01ec95ecbb85b8c76 SHA-1: 0fa497ed705cce7ec610ace1f94823dd1b399ae4 SHA-256: a1171f2d356fcd991e0bb8b5a7d7335f36d97838430ce56a005738e4f82d0049
126 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 high likelihood of malicious intent. The presence of numerous external URIs, many with 'utm_term' parameters suggesting tracking or redirection, points towards a phishing or malware distribution scheme. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create PDF documents from web content, further supporting the idea that the PDF acts as a lure to external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 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://queure.ru/uplcv?utm_term=gta+mod+android+download PDF link annotation
    • https://pottoka.info/files/galeria/files/16408178179.pdfIn PDF document text
    • http://gocchame.vn/app/webroot/img/uploads/files/tobivovenuzugedulenamu.pdfIn PDF document text
    • http://kengosushionlineorder.com/uploads/files/9740853563.pdfIn PDF document text
    • https://dailyiat.com/html_upload/file/tufupekamafafirixa.pdfIn PDF document text
    • http://spy-military-labs.com/userfiles/file/kapabor.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/161384837d8c72---90885704144.pdfIn PDF document text
    • http://irollee.com/userfiles/file/solefufazuvegusideloreb.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16135e987238d9---82295429695.pdfIn PDF document text
    • https://geneticapanama.com/userfiles/file/87066543750.pdfIn PDF document text
    • http://tlumacz-bialystok.pl/pliki/file/jekuvedevejodas.pdfIn PDF document text
    • http://cuacuonbinhduong.com/upload/files/80370868424.pdfIn PDF document text
    • http://phunphu.com/userfiles/file/68764830799.pdfIn PDF document text
    • https://serka.com/serka/upload/files/bifovozewelikupotubos.pdfIn PDF document text
    • https://tinnituskozpont.hu/files/39047836852.pdfIn PDF document text
    • http://agataklimowska.pl/userfiles/file/36664929165.pdfIn PDF document text
    • https://ptogel1.com/contents/files/30581839506.pdfIn PDF document text
    • http://dsfly.com/uploads/files/38966058703.pdfIn PDF document text
    • http://xahscw.com/userfiles/file/rimisavitizogafujumosi.pdfIn PDF document text
    • https://napraforgohotel.hu/upload/file/dugijosogotuxudojutij.pdfIn PDF document text
    • http://gaudi.tw/upload/files/44248876037.pdfIn PDF document text
    • https://zd-zeta.com/uploads/files/202109080244235362.pdfIn PDF document text
    • https://www.hkha.com.hk/ckfinder/userfiles/files/46870668359.pdfIn PDF document text
    • http://www.bluewhaleline.com/image/upload/File/83942375593.pdfIn PDF document text
    • http://alnoorcity.com/userfiles/file/17652842047.pdfIn PDF document text
    • https://loyallcanada.net/editor_files/file/towizijirokuvigabirijes.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_off0000b909.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB909 10232 bytes
SHA-256: f484498e535643d18f5354e926d1dd2b81ab2ef5012f858a56d4ba4337d5e824
font_01_sfnt_off0000cffb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFFB 15968 bytes
SHA-256: 265698d14a6b6f066511dd6460ae6223959757a9b09f02fec2c2150df117d88e
font_02_sfnt_off0000f90f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF90F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1