Malicious PDF — malware analysis report

Static analysis result for SHA-256 8e5c6cdbdeadbfee…

MALICIOUS

PDF

88.1 KB Created: 2021-10-08 07:55:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2065a38dc207f9b23793396be2be0825 SHA-1: f529566682361b99f70a4ec9432fd65ca7509707 SHA-256: 8e5c6cdbdeadbfeebb52a0765e9ab97c275aff0963861a8fae987d9544667ca4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The primary attack pattern involves leveraging these links to deliver a secondary payload or conduct phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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.
  • 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 https://synerhu.ru/uplcv?utm_term=extralinguistic+information+examples
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0ed258bc1c3312efa8501169e8cc298d/tabobifobi.pdf
    • http://sk-uralstroy.ru/uploads/files/76888112328.pdf
    • http://pfmconsulting.org/survey/userfiles/files/viwulujabilawewimipusot.pdf
    • http://nage-z.com/ckfinder/userfiles/files/14444842769.pdf
    • https://mamap.in/ci/userfiles/files/67270748722.pdf
    • http://lhdrum.com/User_File/UpFile/file/20210908224923_YnVzb3Rpbmlsb3dva2lrYXZpbg==.pdf
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/16156087117d3f---23151251385.pdf
    • https://kamarkosong.com/contents/files/nowiwudus.pdf
    • http://poultech.net/d/files/gunedajidazagidaberezaw.pdf
    • http://tchid.net/userfiles/file/xominagitigogek.pdf
    • http://ibsdhc.hpds.work/ecdemo/web/js/ckfinder/files/files/tiworojo.pdf
    • http://toanthinh.vn/webroot/img/files/34989651468.pdf
    • http://graviroz.hu/ckfinder/userfiles/files/23767947648.pdf
    • http://polkovnik.su/upload/file/vomisulimolowesivepov.pdf
    • https://dhesient.com/media/67707474051.pdf
    • http://gokea.org/upload/editor/files/31199555109.pdf
    • http://zjhywt.com/images/upload/File/xebasirawefogetefutap.pdf
    • http://star-transform-moscow.ru/uimg/files/tovitogilitatejenuritonux.pdf
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/3ue8o3c21sqihfntv9nv4i1bhn/xaferegobarejov.pdf
    • http://police8coop.com/UserFiles/file/mizovebejofekaforak.pdf
    • http://redemaisfarma.com/userfiles/file/birogijovom.pdf
    • http://vaynhe.com/upload/files/29498424180.pdf
    • https://megalightgroup.lv/uploads/files/57182393912.pdf
    • https://xn--nmqu14inmf.com/upload/files/natijudilarupofudoza.pdf
    • https://renebeumer.nl/userfiles/file/6044342771.pdf
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/161340188d6bb0---70169721694.pdf
    • 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_off0000e8ef.bin
162835fde052d48a59ae5590680c56e8867ab6d621a51d324a34f0334f929983
pdf-font-stream PDF embedded font (sfnt) at offset 0xE8EF 11008 bytes
font_01_sfnt_off0001028b.bin
eba674969a014c264c0fb207911dea97b33297fed556d8efa97512087617ffd0
pdf-font-stream PDF embedded font (sfnt) at offset 0x1028B 20240 bytes
font_02_sfnt_off0001383d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1383D 16792 bytes