Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b9b6f9b90a709cc…

MALICIOUS

PDF

70.5 KB Created: 2021-09-27 11:00:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: b3991e51158161acd69b69a7f1b0248a SHA-1: 924042db834bf820dd60696ed5155a03ee430177 SHA-256: 8b9b6f9b90a709ccdc1a262cfc087d22075b236bdc82acdaffb05cc06d445567
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to numerous external URLs, many hosted on potentially compromised or disposable domains. The embedded URLs and the nature of the heuristics suggest an attempt to direct users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://jmk.kr/ckfinder/userfiles/files/zewemimonugonel.pdf In PDF document text
    • http://branonperformance.com/ckfinder/userfiles/files/63578730558.pdfIn PDF document text
    • http://kprmk.pl/userfiles/file/10134192920.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/c90a8f74ff56be8be62987a79c03adf8/94717518248.pdfIn PDF document text
    • http://debseven.net/UserFiles/File/96236027085.pdfIn PDF document text
    • http://tcsklife.com/filespath/files/20210913210710.pdfIn PDF document text
    • http://tekizolasyon.com/ckfinder/userfiles/files/30981593194.pdfIn PDF document text
    • http://embeddedhr.com/ckfinder/userfiles/files/7176749218.pdfIn PDF document text
    • http://discus-rus.ru/upl/file/62276173093.pdfIn PDF document text
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fcf0e44723---wupatomukepizopa.pdfIn PDF document text
    • http://citysoupsbellevue.com/uploads/files/39442483303.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/neteki.pdfIn PDF document text
    • http://testplanet.nl/uploads/files/popug.pdfIn PDF document text
    • https://dacola.com/upload/files/67629058049.pdfIn PDF document text
    • https://oykufestivali.com/ckfinder/userfiles/files/kaliwon.pdfIn PDF document text
    • http://bloodfaces.de/attachment/file/jezamejosadununevom.pdfIn PDF document text
    • http://dulichtantai.com/files/uploaded/files/26044211432.pdfIn PDF document text
    • http://77owship.netsociality.com/upload/files/86229919788.pdfIn PDF document text
    • http://lamardaegu.com/upfile/user/file/fewomenomilikapur.pdfIn PDF document text
    • http://ariege.proximeo.com/ckfinder/userfiles/files/4747973886.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613e41a12247e---mevefeginig.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=mm2+value+tradePDF 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_off0000aee3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEE3 10204 bytes
SHA-256: b5326a1f00a7f8b980c5f8a11119a76d3e9bd028c0f016f3c65f8f43eb105046
font_01_sfnt_off0000c5da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5DA 18376 bytes
SHA-256: bd1dd05d0d9ede4442f9a982a0bb6576e40c1c047581dc1d959d9aac8e89909c
font_02_sfnt_off0000f4c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4C2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1