Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c4dfcbc7ccc8103…

MALICIOUS

PDF

80.7 KB Created: 2021-09-20 01:57:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 022b493feb698050b5ea282fda555579 SHA-1: 00edc58f1b5a5c12d719733c6aec225c4ee4a513 SHA-256: 1c4dfcbc7ccc81035f1b7d181f94719b84bf85659fd8e4dbc95e0d658fed7da9
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, and heuristics indicate it functions as a link farm on disposable hosting. The embedded URLs, such as 'https://coretry.ru/uplcv?utm_term=sim+toolkit+off', suggest a phishing or malware distribution attempt. Although no scripts were explicitly extracted, the PDF structure and heuristic findings strongly imply malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://coretry.ru/uplcv?utm_term=sim+toolkit+off PDF link annotation
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16144ca9a4d334---wikepiguwubi.pdfIn PDF document text
    • http://sichera.eu/userfiles/files/47302468586.pdfIn PDF document text
    • http://boletin.alicantehosteleria.com/lib/ckfinder/userfiles/files/58802872314.pdfIn PDF document text
    • http://schoonhovensvrouwenkoor.nl/ckfinder/userfiles/files/26964475318.pdfIn PDF document text
    • http://dailynewsodia.com/assets/ckfinder/core/connector/php/uploads/files/sajat.pdfIn PDF document text
    • https://chulintemple.house-well.com/CKEdit/upload/files/minoj.pdfIn PDF document text
    • http://kuppersbusch.hu/userfiles/files/wonumuxedil.pdfIn PDF document text
    • http://ecohouse-lab.de/userfiles/file/11523636747.pdfIn PDF document text
    • https://robustbrakes.com/administrator/imagetemp/file/gobaviwuxutexarilelapodi.pdfIn PDF document text
    • https://pasarantogel.com/contents/files/44628704677.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/16136c6f21b35d---tatudujas.pdfIn PDF document text
    • http://bekescsaba.varosom.hu/userfiles/files/lezowedapiwefetimolug.pdfIn PDF document text
    • http://regmac.net/userfiles/files/55179753056.pdfIn PDF document text
    • http://philipwillettelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/renazolasemeweso.pdfIn PDF document text
    • https://mlspoland.co/files/file/mexeguveweromuf.pdfIn PDF document text
    • http://dvg.asia/ckfinder/uploadfiles/files/23437709764.pdfIn PDF document text
    • https://bimetoor.com/basefile/bimetoorir/files/11300324382.pdfIn PDF document text
    • http://cy2hand.com/userfiles/pakijesawunat.pdfIn PDF document text
    • http://salondebellezaanamariaromero.es/ckfinder/userfiles/files/redimobisezovawomaz.pdfIn PDF document text
    • http://banghetretunhien.com/media/ftp/file/zabexowibikekorekog.pdfIn PDF document text
    • http://nincity.de/inline/file/fidipiruzojufadu.pdfIn PDF document text
    • http://romanasulcikova.cz/userfiles/gabalexoberupovava.pdfIn PDF document text
    • http://camel-republic.com/media/userfiles/files/54688754489.pdfIn PDF document text
    • http://enotecagaribaldi.it/userfiles/files/gerozomititonatimosujoxir.pdfIn PDF document text
    • http://netisiletisim.com/guvennet/resimlerfiles/sejubib.pdfIn PDF document text
    • http://s292376414.onlinehome.fr/datas/imgmail/file/nidesavolesarox.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_off0000db36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB36 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f34c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF34C 9876 bytes
SHA-256: fb255f34055c299013dfd96a80850e0b8db30164bfe264df95d22b85701b6e36
font_02_sfnt_off00010901.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10901 16968 bytes
SHA-256: 4fcced360e361039957314d4c0b65f340b87b9bdcf65bd3177bb351157edf53a