Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b90ac008a81a0f0…

MALICIOUS

PDF

82.9 KB Created: 2021-09-22 16:23:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: fd5731157c969d8cfacbb58a249027d0 SHA-1: d44680a2966ad2039cc6baa9558e3670c6463da2 SHA-256: 8b90ac008a81a0f0d331e43fa87ca7c9055dfdff9ba936772dbbdeb5b77b249e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting, likely to distribute malware. The presence of a 'download button' lure further supports a malicious intent to trick users into downloading a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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.
  • 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://ourgans.org/userfiles/files/wumonamufonewoja.pdf In PDF document text
    • http://namadagaskare.ru/ckfinder/userfiles/files/lewodutuxit.pdfIn PDF document text
    • http://tks-forever.com/upload/2021/09/01/file/nidepeze.pdfIn PDF document text
    • https://yesilkoyluleriz.biz/resimler/files/71678783948.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161444219638c0---27088195322.pdfIn PDF document text
    • http://greensketch.in/userfiles/file/pogefo.pdfIn PDF document text
    • http://odpadykj.cz/UserFiles/File/18912234129.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1613c64ca7da52---wesasazogelosabak.pdfIn PDF document text
    • http://dmychadla.eu/UserFiles/File/panifirotomide.pdfIn PDF document text
    • https://virker-ikke.dk/files/93480783869.pdfIn PDF document text
    • http://auswallendorf.de/userfiles/file/jitoguderafujak.pdfIn PDF document text
    • http://nt-module.ru/ckfinder/userfiles/files/62054075862.pdfIn PDF document text
    • http://szerecsengyogyszertar.hu/editor_up/fapuwibadozodevisobevepa.pdfIn PDF document text
    • http://inannamsao.com/uploads/files/kevaluwib.pdfIn PDF document text
    • http://php-lounge.de/userfiles/file/57041210923.pdfIn PDF document text
    • https://at-studio.tw/app/webroot/userfiles/files/20210904_212136.pdfIn PDF document text
    • https://parvazyab.com/basefile/api203/files/wenuxan.pdfIn PDF document text
    • http://santeh.md/img/files/womepoj.pdfIn PDF document text
    • https://hamzakocakoglu.com/userfiles/file/92609005518.pdfIn PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/dcc0fac9599e20313d36b46dc18322ee/gafuzixomebaxewem.pdfIn PDF document text
    • http://henanshuangxin.com/d/files/45753320833.pdfIn PDF document text
    • https://dagvandearchitectuur.be/_files/file/busabilajipokekuzonif.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=free+fire+mod+apk+100+workingPDF 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_off0000d836.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD836 19764 bytes
SHA-256: 88c702698f247254465abf968e2b171fd8b0a76347ab7efc2f52290205080c9c
font_01_sfnt_off00010cf1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CF1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012508.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12508 10860 bytes
SHA-256: d0ede3b69870a3ca405f961565e6efa0a35b25df41339fdc52f1d2ec941206b5