Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5590fd2aa605747…

MALICIOUS

PDF

87.2 KB Created: 2021-09-23 20:56:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3bff643f0aa6a3b66d253c0fd85a8994 SHA-1: 5b4fd8a54217f0bb4757e9592978285ba5836d44 SHA-256: f5590fd2aa60574727868eb29a73cd135290ef0fa8ff6b72a5f0bd2b3d5e26c6
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and is identified as a link farm pointing to compromised websites and disposable hosting. The presence of embedded JavaScript, combined with the link farm, suggests an attempt to lure users to malicious sites, likely for phishing or to download further malware. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://philabc.ru/uplcv?utm_term=skull+movie+app
    • http://zafirkort.com/uploads/files/93267258058.pdf
    • http://csim.jp/ckeditor/uploads/files/zidafetokisuraxetaximet.pdf
    • http://labmansour.com/app/webroot/js/ckfinder/userfiles/files/zanumezoxiginef.pdf
    • https://corumosmanlimakina.com/js/ckfinder/userfiles/files/3658291095.pdf
    • http://women-for-marriage.com/ckfinder/userfiles/files/metevomonip.pdf
    • https://sibservis.com/ckfinder/userfiles/files/78084170090.pdf
    • https://www.solucionaesp.com/ckfinder/userfiles/files/39674906593.pdf
    • http://richmore.kr/uploadfile/fckeditor/file/13056110607.pdf
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fc6b244465---vufatuzeruji.pdf
    • https://resortweeks.pro/userfiles/file/dugajapafasivolizomino.pdf
    • http://libron.pl/fckupload/assets/file/34248361240.pdf
    • http://cgpharma.in/cote_dor_import/admin/ckfinder/userfiles/files/89362190913.pdf
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161482241e56a9---lexamut.pdf
    • http://yilip.net/userData/board/file/rugufezufolunu.pdf
    • http://trivio.it/userfiles/files/wubirerevel.pdf
    • http://constantemails.com/userfiles/file/1630904307xilepelubarejafijal.pdf
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141f229dab0b---luvavilopowinokekivezu.pdf
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614860af60a11---dikisewuwog.pdf
    • http://nitexprofi.cz/userfiles/file/supufawetus.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f0ea.bin
b501d42c834a4c46f7af8f76bff67c8099a8152cfc5d1bd3b5de0970580a8de1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0EA 18560 bytes
font_01_sfnt_off00012080.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12080 16792 bytes
font_02_sfnt_off00013897.bin
c2028aaee5656f8499211ccd16fe0e544606f10539890364cceca286364ecfdd
pdf-font-stream PDF embedded font (sfnt) at offset 0x13897 10276 bytes