Malicious PDF — malware analysis report

Static analysis result for SHA-256 a81144553459a5cf…

MALICIOUS

PDF

71.6 KB Created: 2021-09-26 00:13:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 61b1e0a3fa2a5c1d40f95f91293c027f SHA-1: 10be1034bc55583bd474c41a3c102265b0bd8c8d SHA-256: a81144553459a5cf0bb3b18ba9c4930d29cbb9ccbd2eb7b47268f1ed3fd7c8c0
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ee98227ba2---83471146493.pdf
    • http://twsl.mingann.info/upload/ckfinder_temp/files/20210909044811.pdf
    • http://sadvita.lt/pav/file/66518923570.pdf
    • http://akiyastyle.com/app/webroot/js/ckfinder/userfiles/files/dekuxufegabaripig.pdf
    • http://wamaeassociates.com/images/uploads/originals/file/kipumajiw.pdf
    • http://beccaro.it/userfiles/files/porefilunesexobumijis.pdf
    • https://learnrkbin.jugalbandiresearch.com/ckfinder/userfiles/files/niwogagube.pdf
    • http://addisonplaza.abwingsmd.com/uploads/files/12536112947.pdf
    • http://expertsystemgroup.com/file_media/file_image/file/24200780837.pdf
    • http://starwindows.ie/ckfinder/userfiles/files/56084140456.pdf
    • http://sipzip.com/userfiles/file/pibofugajomofodevolu.pdf
    • http://vanxuantravel.com/upload/files/60547850672.pdf
    • http://ccadl.com/files/20210904222608.pdf
    • https://radiosmile.hu/upload/file/vapifivodi.pdf
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f01d2dfde4---64298290957.pdf
    • http://xn--oy2b9bv81anouola.com/upload/file/202109130715580844.pdf
    • https://soportedevida.mx/ckfinder/userfiles/files/sejuniwijeribevusenaritot.pdf
    • http://sportsclinicwest.ie/media/contents/file/vuzegebonit.pdf
    • http://gestaocipa.com/public_html/Imagens/file/nepexarotemepugobot.pdf
    • https://maymac.info/userfiles/file/wuwuruzibedegug.pdf
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/fd1a404913cd0f7e1da77059b4f52a28/tisidajokuwabunapejik.pdf
    • http://onthebroadway.com/CPD/adminpanel/upload/file/79748972637.pdf
    • https://www.spitalmoldovanoua.ro/ckfinder/userfiles/files/92356234732.pdf
    • http://mygiftltd.com/userfiles/file/44910996618.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=create+vpn+app+android+studio
    • 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_off0000b2c4.bin
5b0af09fd03ddd40b403058802d13289a4a12b29084601f0c745c8ce335e048c
pdf-font-stream PDF embedded font (sfnt) at offset 0xB2C4 10536 bytes
font_01_sfnt_off0000caef.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCAEF 16792 bytes
font_02_sfnt_off0000e301.bin
b97da91ecb4bb1d22afd1b46535b59bca4fca8d65172c1cd841a9f65ba1d1408
pdf-font-stream PDF embedded font (sfnt) at offset 0xE301 17908 bytes