Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4a4e7b4b10d300c…

MALICIOUS

PDF

70.8 KB Created: 2021-09-27 04:57:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 091660be962890bcdfd993a72e432f56 SHA-1: b99c17f521a08b9abd434227ea568523f262438e SHA-256: f4a4e7b4b10d300c70f379b05272d791017952a7a9a2271812b3f3ec581c49d5
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous embedded URLs pointing to various domains, suggesting a link farm or redirection mechanism to phishing sites. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM indicates a deliberate attempt to create a network of disposable hosting for these links. While no scripts were explicitly extracted, the nature of the embedded URLs and the 'Phishing' classification strongly suggest a phishing or credential harvesting attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://drafthe.ru/uplcv?utm_term=free+rublins+generator PDF link annotation
    • http://chanakyaaerospacedefence.com/userfiles/file/11550286305.pdfIn PDF document text
    • http://iowatriallawyer.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/66510937581.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/161454cc18371a---72694773303.pdfIn PDF document text
    • https://mundolibre.cl/uploads/userfiles/files/4621474663.pdfIn PDF document text
    • http://amandatravel.com/userfiles/file/10746785055.pdfIn PDF document text
    • http://aurora-c.jp/files/files/wexajuzi.pdfIn PDF document text
    • http://terhautz.com/upload_files/files/lulixogalojepurugo.pdfIn PDF document text
    • https://economiadecomunion.net/ckfinder/userfiles/files/lipuxujemisanoposo.pdfIn PDF document text
    • http://alfatreyd-mebel.ru/archive/images/file/44903700912.pdfIn PDF document text
    • http://sfipl.in/userfiles/file/57861703633.pdfIn PDF document text
    • http://indianspringhomes.com/userfiles/files/2848169750.pdfIn PDF document text
    • https://perbloland.com/userfiles/file/tejalesaxedorifowavom.pdfIn PDF document text
    • https://mashura.co/userfiles/files/76638918787.pdfIn PDF document text
    • http://terrietanaka.com/library/files/49428820163.pdfIn PDF document text
    • http://homesunshinepharma.com/upload/files/95957775560.pdfIn PDF document text
    • https://segurodegranizo.ar/noticias/fckeditor/file/40215546139.pdfIn PDF document text
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/8dec4c8477c5303acc807d1618f3c952/28355420991.pdfIn PDF document text
    • http://bibliotekaszamocin.pl/img/upload/files/86806037192.pdfIn PDF document text
    • https://akvaguru.hu/user/file/talikunubirasix.pdfIn PDF document text
    • https://briljant-maleri.se/UserFiles/files/83502786431.pdfIn PDF document text
    • http://www.anglometais.com.br/adm/Editor/ckfinder/userfiles/files/vawizawufolaxofovu.pdfIn PDF document text
    • https://hoalavender.net/upload/files/vivomowosexuzabapopa.pdfIn PDF document text
    • http://loaamtran.vn/files/usersfiles/files/78704322073.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_off0000b2f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2F7 16556 bytes
SHA-256: 125cd2733d689958a74b0f61053e709d564617043d864cca17e4fc6af403e743
font_01_sfnt_off0000dd08.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD08 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f51f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF51F 10500 bytes
SHA-256: 0b6ac5acbf05e6c9602f47a3bd150b2db4f2ff5ce11f1285ae94c815e7bef64d