Malicious PDF — malware analysis report

Static analysis result for SHA-256 d61a1acb4692dbe4…

MALICIOUS

PDF

87.3 KB Created: 2021-09-21 04:01:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: f10e22387990bd0a7bfb4d3b7069f3aa SHA-1: 917f16cabb8bc1a559eec846240529c3926c6e96 SHA-256: d61a1acb4692dbe408fae98cf1324fb27c8efa72225d519051d8cf8b042320e5
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of external URLs, many pointing to disposable or unknown domains, consistent with a link farm designed to distribute malicious content or phish for credentials. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a deliberate effort to create a link farm on potentially disposable hosting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://kenkochaya.com/user_data/ckfinder/files/pupupa.pdf In PDF document text
    • http://samtekelektrik.com/files/19038406023.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1612fdfd44c3e4---24208133781.pdfIn PDF document text
    • http://fibertechnique.com/tmp/file/wifogisila.pdfIn PDF document text
    • http://boldogelet.hu/media/lesaker.pdfIn PDF document text
    • http://gaudi.tw/upload/files/63992017850.pdfIn PDF document text
    • https://sunnyrosesschool.com/userfiles/file/kekadajimatoxig.pdfIn PDF document text
    • http://zensushidanapoint.com/uploads/files/62842242965.pdfIn PDF document text
    • http://ateliergermain.org/sites/default/files/file/vofemomomupukibojuwolon.pdfIn PDF document text
    • http://smeeing.com/userfiles/files/ligufitedobilekixezumosa.pdfIn PDF document text
    • http://russia-ex.com/images/blog/file/52823392445.pdfIn PDF document text
    • http://hotelbellevuepalermo.com/userfiles/files/65908111685.pdfIn PDF document text
    • https://artbynela.com/uploads/file/26569362988.pdfIn PDF document text
    • https://swift-tw.com/lcc/upload/files/95773183494.pdfIn PDF document text
    • http://bzws.zhanyougame.com/ckfinder/userfiles/files/ranitojivodofupa.pdfIn PDF document text
    • http://avtokapriz42.ru/userfiles/file/92726005205.pdfIn PDF document text
    • https://vishalahospitality.com/ckfinder/userfiles/files/78716417908.pdfIn PDF document text
    • http://xedaptap.net/userfiles/file/pijapi.pdfIn PDF document text
    • http://irpuyesh.com/cache/fck_files/file/solakaxe.pdfIn PDF document text
    • http://amsuatrust.org/survey/userfiles/files/51011718675.pdfIn PDF document text
    • https://www.milestonesmn.org/ckfinder/userfiles/files/gupatamowod.pdfIn PDF document text
    • https://thaibamboorestaurant.ca/phpsites/bard_ford/uploads/file/saveram.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=watch+old+classic+movies+online+freePDF link annotation
    • 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_off0000f21c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF21C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010a2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A2E 17520 bytes
SHA-256: 841bcccd940382b30bbc92495a1f29074871f26e128067659a312acf97781cfd
font_02_sfnt_off00013738.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13738 10800 bytes
SHA-256: b8a1226afad7b89b1ebdae6a4af593a9da3590870e2edf1319209f4ee12b51b5