Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c99d2456b6f3c3b…

MALICIOUS

PDF

81.6 KB Created: 2021-09-16 13:01:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5f36c7e7f31fec981a44be409ca47c06 SHA-1: e985a1a2087dc88f660a2c5ece67f638617106a6 SHA-256: 6c99d2456b6f3c3b476afaf9d5d5abe34b136d0b1d3b7e53ef792d99ca8a6303
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple domains, some of which are hosted on compromised CMS uploads. The presence of 'utm_term' parameters in some URLs suggests an attempt at SEO manipulation or tracking. No scripts were extracted, but the overall structure and detection indicate a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • 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.
  • 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://artwatch.ru/userfiles/file/luwejujogameguzazalebun.pdf In PDF document text
    • http://norilskgu.ru/userfiles/file/mugofejaluxusev.pdfIn PDF document text
    • https://giltmorestukko.hu/ckfinder/userfiles/files/36052717637.pdfIn PDF document text
    • https://www.burnat-provins.ch/ck/ckfinder/userfiles/files/popafiwilusax.pdfIn PDF document text
    • https://vico-inmobiliaria.com/ckfinder/userfiles/files/nupimevuduj.pdfIn PDF document text
    • http://fredericjean.net/oplusco/file/nosuzefewuloxini.pdfIn PDF document text
    • https://www.jdconstinc.com/ckfinder/userfiles/files/74928746689.pdfIn PDF document text
    • http://gmtshipping.com/attachment/file/97852975693.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/161329f9f4f960---8775886243.pdfIn PDF document text
    • https://natinsel.com/imagenes/file/sidowoloxukuledadomi.pdfIn PDF document text
    • https://bankubezpieczen.pl/userfiles/file/68152333400.pdfIn PDF document text
    • http://inewbus.com/wp-content/plugins/super-forms/uploads/php/files/t693gf8qh141r21gub3mil0036/jogipesomul.pdfIn PDF document text
    • http://emekyesiltepe.net/images_upload/files/62589932599.pdfIn PDF document text
    • http://goforthegreengolfpools.com/userfiles/file/81710384273.pdfIn PDF document text
    • http://mnwebdesign.dk/userfiles/file/kajikefufapor.pdfIn PDF document text
    • https://escolaalfa.com/userfiles/file/vusepogazosomarere.pdfIn PDF document text
    • http://aqua4you.hu/userfiles/file/92964681014.pdfIn PDF document text
    • https://nakatarikaszel.pl/app/webroot/userfiles/file/wiradawokotuminoseku.pdfIn PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/bc0cfb0eb77c9d78d23f40c115009832/fusepidu.pdfIn PDF document text
    • http://www.ddu-hk.cz/ckfinder/userfiles/files/38042663179.pdfIn PDF document text
    • http://damutech.kz/upload/2021/09files/210901093311298061jta35.pdfIn PDF document text
    • http://aotwresort.info/ckfinder/userfiles/files/kozifi.pdfIn PDF document text
    • http://wedding-box100.com/uploads/files/202109131002166113.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=mobile+legends+hack+no+rootPDF 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_off0000db4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB4E 17444 bytes
SHA-256: cca31c28eb66ef9ea41a50c3293423646ba5f2d71ddf66a43d680d4f79c4c707
font_01_sfnt_off000107f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107F7 10876 bytes
SHA-256: 5a929a38b8fd19e31f8a3a49b42848f8b3284f8f0870d78dbc9d72d9631b9123
font_02_sfnt_off000120d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120D7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1