Malicious PDF — malware analysis report

Static analysis result for SHA-256 a739a7436b0cb368…

MALICIOUS

PDF

73.4 KB Created: 2021-09-30 10:04:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 6b8e0bfdb26333a480ee6c00860a222a SHA-1: f0ed9fe341100736099cdaf4fe3cd0745855f924 SHA-256: a739a7436b0cb36825a144d37a047ada95f56eeb7dcf74abf1d5ae5ed7415626
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a machine learning classifier and ClamAV, indicating malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests it functions as a link farm, directing users to numerous distinct and potentially disposable domains. The presence of external URIs and embedded URLs further supports this, with many pointing to PDF files, likely serving as lures or further stages of a campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://drafthe.ru/uplcv?utm_term=descargar+recuva+para+android+apk PDF link annotation
    • https://nslogisticservice.com/userfiles/files/91558931216.pdfIn PDF document text
    • http://toshiteriyakiburien.com/uploads/files/pimikufajaropibanuf.pdfIn PDF document text
    • http://romovi.net/sgi_userfiles/userfiles/files/fuwilalovatajuk.pdfIn PDF document text
    • http://happinessgown.com/upload/users/files/95913290699.pdfIn PDF document text
    • https://nawaasha.org/userfiles/file/fujadonutib.pdfIn PDF document text
    • http://nj-rshb.com/v15/Upload/file/20219281216462465.pdfIn PDF document text
    • https://pima-alarms.eu/slicice/file/lipivudoxolokusufiritew.pdfIn PDF document text
    • http://omeofest.eu/userfiles/files/80405990503.pdfIn PDF document text
    • https://sensiblemachines.com/ckfinder/core/connector/php/files/46805235385.pdfIn PDF document text
    • http://www.sictombbi.fr/ckfinder/userfiles/files/57589567989.pdfIn PDF document text
    • http://wsm.hk/images/uploadfiles/file/tolitoj.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/nubatuxado.pdfIn PDF document text
    • http://fobosgrunt.ru/files/ckfinder/files/40522937252.pdfIn PDF document text
    • http://getrade.net/uploadfiles/file/gepepagozuwimima.pdfIn PDF document text
    • http://arsvet.ru/img/upload/12632335070.pdfIn PDF document text
    • http://bestpokeya.com/uploads/files/rekusidiwusefuxave.pdfIn PDF document text
    • http://cosmik-kinoteatr.ru/sadm_files/pakozixabes.pdfIn PDF document text
    • http://jpsacademy.com/slbdavbatala/userfiles/file/41810708621.pdfIn PDF document text
    • https://travellifeafrica.com/ci/userfiles/files/33965789045.pdfIn PDF document text
    • http://cp-1.ru/userfiles/files/73612198578.pdfIn PDF document text
    • http://steffis-strassladen.de/userfiles/file/79896304717.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/1614ee63192557---velitutabinemaluwi.pdfIn PDF document text
    • http://ellev.fr/upload/files/75627735507.pdfIn PDF document text
    • http://seashinechina.com/admin/fckeditor_upfiles/file/2021092300151780554.pdfIn PDF document text
    • https://et-auditing.com/userfiles/files/lenor.pdfIn PDF document text
    • http://jolanyee.com/upload/files/202109210351135486.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_off0000b695.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB695 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cea7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEA7 19060 bytes
SHA-256: ee7a0ae7606856a0ae02d6e91fbb82ae569183c529a517fb24e733d0b701fb64
font_02_sfnt_off0000ff43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF43 10804 bytes
SHA-256: 5062f9d33a759f193f00cd9e9519b7a78ccc5c512393dbf4e141cd4a59d2a79e