Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8e21fed3dad6c7c…

MALICIOUS

PDF

75.7 KB Created: 2021-09-08 13:47:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: feddd126da56bf62fd2bf2a7c02b9921 SHA-1: de81f9af4526f942338ffb5d1931dbf13900e67d SHA-256: c8e21fed3dad6c7c3acf9dce74347e0110e79cbc2acd2665fbc0e81f2515665e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs, with one heuristic specifically identifying it as a link farm on disposable hosting, suggesting a phishing or malware distribution lure. Although no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it is designed to redirect users to malicious external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://amatnieks.com/pictures/image/zevitunev.pdf In PDF document text
    • http://mvsexpo.ru/admin/ckfinder/userfiles/files/bijokerawavemofiximivuvus.pdfIn PDF document text
    • http://www.rupankar.com/fckimages/file/16408829213.pdfIn PDF document text
    • https://mavachhaiphong.com/upload/files/44684131758.pdfIn PDF document text
    • http://getsolarnj.com/userfiles/file/19404047365.pdfIn PDF document text
    • https://supermovi.com/userfiles/files/98913764535.pdfIn PDF document text
    • http://kimsanghun.com/upload/userfiles/file/2021951445433558.pdfIn PDF document text
    • https://sesconbs.org.br/ckfinder/userfiles/files/duduzufapawakedoxis.pdfIn PDF document text
    • https://insinkerator.us/images/uploaded/file/34958233500.pdfIn PDF document text
    • http://agriturismolionsfarm.it/userfiles/files/zetejonelafofudalaxuv.pdfIn PDF document text
    • http://z-sinpro.com/upload/files/91035808207.pdfIn PDF document text
    • https://cochleartudaskozpont.hu/files/8310274064.pdfIn PDF document text
    • http://saharun.org/uploads/ckfinder/userfiles/files/7592786253.pdfIn PDF document text
    • http://praguetransfer.com/files/file/feparodaj.pdfIn PDF document text
    • https://agermag.ro/mm/file/sitepodudasoko.pdfIn PDF document text
    • http://teaterskolen-efteruddannelsen.dk/ckfinder/userfiles/files/vinosajukugunejoz.pdfIn PDF document text
    • https://ermolino.mebel18.com/uploads/files/zevipuzewesifa.pdfIn PDF document text
    • http://www.insight-assessment.com/ckfinder/userfiles/files/8946927397.pdfIn PDF document text
    • https://gagiongvitgiong.com/ckfinder/userfiles/files/28493671044.pdfIn PDF document text
    • http://bctlorraine.org/userfiles/file/70188982040.pdfIn PDF document text
    • http://www.drivingschool-brno.cz/files/files/galezugifetiduwebug.pdfIn PDF document text
    • https://lmbri.com/WYSIWYGImage/file/80146980414.pdfIn PDF document text
    • http://chikatere.com/Upload/files/totujiluf.pdfIn PDF document text
    • http://dachastyle.com/userfiles/file/vajokoje.pdfIn PDF document text
    • https://groupburuemas2.com/contents/files/vezegekukixusamoko.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=proofreading+and+editing+worksheets+year+5PDF 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_off0000c2e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2E3 11012 bytes
SHA-256: feeaab4ad3858a2df5ca7dbfae82f4845b5deb8e3faa3d21b2488cc443d555ce
font_01_sfnt_off0000dc5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC5B 17220 bytes
SHA-256: 76db1f945e608b8582d2a25e31ff9a01f92ada15e2525a63555508e7e44ca42d
font_02_sfnt_off0001091d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1091D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1