Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f1fa84437e517a9…

MALICIOUS

PDF

87.4 KB Created: 2021-09-12 23:51:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: f2336cc80d21f22273e14505a9016afe SHA-1: c8ac07cb0d7822806ae2ade4b512d698232b80ef SHA-256: 1f1fa84437e517a914439cdd9fc76653daf1f174521ccc3e4de3d43617acae75
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to a link farm, as indicated by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the nature of the link farm and the presence of embedded URLs suggest a phishing or malware distribution scheme, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://amsaneeraus.fi/userfiles/files/zerafupogikozixi.pdf In PDF document text
    • http://alessandrobelleseveterinario.eu/userfiles/files/kunax.pdfIn PDF document text
    • https://chasehr.in/userfiles/file/xevup.pdfIn PDF document text
    • https://pianotuningdarwin.com/userfiles/files/xudugipupa.pdfIn PDF document text
    • http://chamdure.com/DATA/files/23357123649.pdfIn PDF document text
    • https://china-glass-mosaic.com/userfiles/files/20210910_183538.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613234f623ab3---59766811398.pdfIn PDF document text
    • http://rund-sro.cz/UserFiles/File/pejesokinepuzikavowibe.pdfIn PDF document text
    • http://gift-founder.com/archive/upload/files/lakize.pdfIn PDF document text
    • http://szcftz.com/upload/lijovi.pdfIn PDF document text
    • http://lignumweb.com/site/webroot/uploads/files/vigamutujoxegalirirofel.pdfIn PDF document text
    • http://bfcy88.com/uploads/files/81980997710.pdfIn PDF document text
    • http://xn--9i1b14l32gg2dsybq3b.com/upload/fckeditor/file/gisikewinupipebolazibiv.pdfIn PDF document text
    • https://tavcam.com/upload/ckfinder/files/8328736506.pdfIn PDF document text
    • http://yuanhebiotech.com/upload/files/62156681299.pdfIn PDF document text
    • https://www.institutvzdelavani.cz/files/94982286820.pdfIn PDF document text
    • http://111-orte.de/testarea/cwsCMSlight/media/files/zuwetowilim.pdfIn PDF document text
    • https://volpatoebrum.com.br/_common/admin/scripts/ckfinder/userfiles/files/91614923483.pdfIn PDF document text
    • http://emanuelmlevin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/49505093589.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/ad108545809100945fffa7b26f362add/32142373549.pdfIn PDF document text
    • https://www.meditech.cz/ckfinder/userfiles/files/32668593401.pdfIn PDF document text
    • https://afra24.com/basefile/afra24/files/46414768507.pdfIn PDF document text
    • https://cqhuaan.myhost360.cn/upload/files/09-02-05-49-46-16.pdfIn PDF document text
    • http://poptheme.cn/uploadfile/files/20210902_030516.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=samsung+s8500+androidPDF 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_off0000f0a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0A0 18336 bytes
SHA-256: 79fb0dfbf89fdab2b4949c4d995b06b41374cde01ab0481e1931067be80ec5f1
font_01_sfnt_off00011f31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F31 10956 bytes
SHA-256: f2338c04e7319fa3e57023bb98c9ce6f635674724dd5f9e33ff548d4509ca76a
font_02_sfnt_off0001384d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1384D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1