Malicious PDF — malware analysis report

Static analysis result for SHA-256 6cf4fdb5242257b2…

MALICIOUS

PDF

81.3 KB Created: 2021-09-13 03:28:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 2273bfbc8f63226f6fcea7de4bb41b5f SHA-1: f5c76b9be4831edc4ca1976159c83864450eced2 SHA-256: 6cf4fdb5242257b2926c43e8c6d8969ed6776ae0434f156171e0f10d51f8577e
164 Risk Score

Malware Insights

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

The PDF contains a link farm hosted on disposable domains, with multiple links pointing to PDF files. One heuristic specifically identifies this as a 'PDF SEO Disposable Link Farm' and another flags it as a 'PDF link farm points to compromised-WordPress upload storage'. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to deliver a payload via the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://hometextiles-consultant.com/ckfinder/userfiles/files/majemixejemaboxupokonawun.pdf In PDF document text
    • http://pop-around.com/file_media/file_image/file/bovevavevofux.pdfIn PDF document text
    • http://positiveforce.in/uploads/files/felonoxuxamoxodis.pdfIn PDF document text
    • http://turskazka.ru/ckfinder/userfiles/files/22941248679.pdfIn PDF document text
    • https://eastmangroup.org/ckfinder/userfiles/files/vowixaxirejowegivituku.pdfIn PDF document text
    • http://gr-chem.com/upload/files/kekiruve.pdfIn PDF document text
    • http://www.physedu.in/newsite/userfiles/files/nalavirexogawexiwatavi.pdfIn PDF document text
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e3f8fe7bb6---virorivajoviwo.pdfIn PDF document text
    • http://candleelectricals.com/uploaded_files/userfiles/files/3611765335.pdfIn PDF document text
    • http://naplesredeals.com/userfiles/files/38512235268.pdfIn PDF document text
    • http://valkexclusief.reviews/app/webroot/files/userfiles/files/pexilozunupigo.pdfIn PDF document text
    • http://gdfsztal.com/uploadfile/files/83898163757.pdfIn PDF document text
    • http://edallyshop.com/upload/files/xigalikewoxamilarujejelun.pdfIn PDF document text
    • https://evrenmentese.com/upload/ckfinder/files/5494204768.pdfIn PDF document text
    • http://mobil-tech.com/files/91823634113.pdfIn PDF document text
    • http://www.thunderesp.com/ckfinder/ckfinder.htmlfiles/netoxesajatemigenorulef.pdfIn PDF document text
    • http://x-mobio.com/upload/files/9107381038.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee5186af71---pelonijerefiki.pdfIn PDF document text
    • http://sambometal.com/dataroom/file/70653702027.pdfIn PDF document text
    • https://acrgroup.nl/userfiles/file/92052904114.pdfIn PDF document text
    • http://elementyzlaczne.pl/media/file/rufupinosig.pdfIn PDF document text
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16135ca64023d5---54765666750.pdfIn PDF document text
    • http://www.jasolasia.com/image/upload/File/bepusi.pdfIn PDF document text
    • http://asiavent.com/UserFiles/file///jolavudewupejomuzovagiza.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=pokemon+xy+game+download+for+android+mobilePDF 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_off0000d656.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD656 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE6D 10964 bytes
SHA-256: a3d3aedf81ec9c586c14820768a1b835d63b2a6dcf8b767889e177cfae82575a
font_02_sfnt_off000107ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107AE 18272 bytes
SHA-256: f740cdf8d85abd841bb1df566750c0e0a365437c001e1def20d0e3a24f180416