Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac3ed553afd1d516…

MALICIOUS

PDF

86.0 KB Created: 2021-09-22 21:12:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 874f4a6ef6c2d4426c89b6d50c47afc8 SHA-1: 678a9fea05974b4c84cd45ef6c835a372ca2a553 SHA-256: ac3ed553afd1d51670c229c7cff054380e4dae19a8cd81f30032efd553b14b96
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of links pointing to various domains, many of which are identified as compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with a link farm used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

Heuristics 6

  • 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.
  • 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://weingut-suppan.at/files/tuwepibesoli.pdf In PDF document text
    • http://iccarrentals.com/files/file/ligofomiteleva.pdfIn PDF document text
    • https://crownprolaw.cn/userfiles/Proj_Name/files/gawowopasizerajirej.pdfIn PDF document text
    • http://spiregene.com/image/files/20210903_054416.pdfIn PDF document text
    • https://www.cifphosteleriayturismo.es/ckfinder/userfiles/files/temidisurisaxerabasovufaz.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16131f7fdc7317---kafaku.pdfIn PDF document text
    • https://nabijdefossa.nl/upload/files/35961983014.pdfIn PDF document text
    • https://ekselantechnology.solutions/ckfinder/userfiles/files/84376314958.pdfIn PDF document text
    • https://navoloki.mebel18.com/uploads/files/50307944296.pdfIn PDF document text
    • http://kfnmdg.com/upfolder/e/files/20210919090632.pdfIn PDF document text
    • http://geosond.pl/userfiles/file/mugil.pdfIn PDF document text
    • http://www.hydro-tg.pro/upload/file/13596504257.pdfIn PDF document text
    • http://www.alfapilates.pl/upload/file/14934756832.pdfIn PDF document text
    • http://globalcenterhotels.com/bot/ckfinder/uf/files/lotapewupe.pdfIn PDF document text
    • https://perfecthospital.org/ckfinder/userfiles/files/janimidaduwifoxuzuja.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b572015e5e---28204554257.pdfIn PDF document text
    • https://hkbca.org/UploadFiles/file/20210907180453185.pdfIn PDF document text
    • http://azseal.net/uploads/userfiles/file/34034994226.pdfIn PDF document text
    • http://desiaussies.com/ckeditor/uploads/files/worarimaxevopirafakinuwal.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149a6f5d3892---lisesifutetaludekejateg.pdfIn PDF document text
    • https://www.tratedu.net/ssss2018/assets/143ad273/ckfinder/core/connector/php/upload/userfiles/files/a6124a84d2faad157d19dfa4ffd372e9.pdfIn PDF document text
    • http://youngshiny.com/userfiles/file/1631102826.pdfIn PDF document text
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/38c45a4fc47b9c299cc5dc25d8c696c8/fijakorogupuzin.pdfIn PDF document text
    • https://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/161460f7b39292---98483221442.pdfIn PDF document text
    • http://falconltd.pl/cache/file/boxuleposadurogazogegoj.pdfIn PDF document text
    • http://palestraarkadia.it/userfiles/files/48503182158.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=windows+phone+os+on+androidPDF 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_off0000ea62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA62 18564 bytes
SHA-256: 606090b3fc000e0a735c05984ab074987d650e51709c11a36f1f91d1e0e42c85
font_01_sfnt_off00011a67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A67 10424 bytes
SHA-256: bb31851c634c3778e1f6ab4f62b9609de6043e7511fcdfb2be86467d804775a1
font_02_sfnt_off000131fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131FD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1