Malicious PDF — malware analysis report

Static analysis result for SHA-256 b13ecb0152f7f635…

MALICIOUS

PDF

88.6 KB Created: 2021-07-19 11:26:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-18
MD5: 273c01cd05f024b9518e0f620a01a41b SHA-1: 96fc2d9b6d6f9ac05f21e32ad89c51afb7439963 SHA-256: b13ecb0152f7f63549418f49a0299d4d0012cec568008e74d4901177affae26d
236 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059 Command and Scripting Interpreter

This PDF document exhibits characteristics of a social engineering attack, specifically a 'ClickFix' variant, by instructing the user to execute a command. The presence of multiple links to compromised CMS upload storage and disposable hosting suggests an attempt to host and distribute malicious payloads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely involving the download and execution of a secondary stage.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • ClickFix social engineering attack high SE_CLICKFIX
    Document instructs the user to press Win+R or paste a command into a terminal — consistent with ClickFix attacks that bypass macro restrictions by tricking users into running malicious commands directly
  • 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 https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/160d7c64f717ce---26409497089.pdf In PDF document text
    • http://tuzlakart.com/files/ximawosoja.pdfIn macro / runtime command snippet
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1606efe89e50ae---bexapenimov.pdfIn PDF document text
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160b21e2ec7788---23283791473.pdfIn PDF document text
    • http://wami.cc/data/files/rokuturutojujunofaris.pdfIn PDF document text
    • http://master-sign.ru/ckfinder/userfiles/files/delifide.pdfIn PDF document text
    • http://chieusangducphat.com/uploads/userfiles/file/50464857358.pdfIn PDF document text
    • http://mrsinternationalbeautypageant.com/clients/8/8c/8c0f0497d7166b07b5568c04be8084ca/File/91089194344.pdfIn PDF document text
    • https://rubyyadav.com/nbloom/fckuploads/file/magodivikuduboj.pdfIn PDF document text
    • http://jmdfhjl.com/fckeditor/userimages/file/87024796335.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/03d6a6551a51fa3210a9c8202bb20532/rawupunerejononoseb.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/ad49a368314c0cfe27c01c801b3f509b/89447609551.pdfIn PDF document text
    • http://chaukitchen.com/uploads/files/zojuzujekabubonuv.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/2ba055355547e292e2e9d59b9af344ac/62052683858.pdfIn PDF document text
    • https://vresponse.net/userfiles/file/bulijik.pdfIn PDF document text
    • http://ned.ru/uploads/files/27337644120.pdfIn PDF document text
    • http://starkhigh1972.com/clients/d/dd/dd83d6d7846a033806cdb512e10d7d7c/File/76584784654.pdfIn PDF document text
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/dab59b7b6a6fe92cdb356858a0125b10/jepipafifu.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606ec8e266119---jebuxorulesareg.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/160c5abeb937c5---fubuzuvusafimilefebugomu.pdfIn PDF document text
    • http://daindnc.com/fckeditor/userfiles/file/81274952275.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/160ad99f83ec28---ravosonepiniximosafegigaz.pdfIn PDF document text
    • https://realestateconnect.pro/wp-content/plugins/super-forms/uploads/php/files/o26vrj8vcgipk1vp8j8j81q4r2/jivagajokitafegeveb.pdfIn PDF document text
    • https://www.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c950b996a03---66019303638.pdfIn PDF document text
    • http://debandhelder.nl/ckfinder/userfiles/files/lateligetufiponim.pdfIn PDF document text
    • https://taichielite.com/louis/taichi/ckfinder/userfiles/files/fafemumigo.pdfIn PDF document text
    • https://www.bluegreenshouseboats.in/wp-content/plugins/fIn macro / runtime command snippet
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=create+partition+using+cmdPDF 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_off0000f225.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF225 10940 bytes
SHA-256: 17ce50fcb963524f05d84ae0a376ae802de1ec8685c56916853fe409220d0a24
font_01_sfnt_off00010b53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B53 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012365.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12365 19168 bytes
SHA-256: 4b8429316c62304bfaaa8c4139a9b4ce00adc8a2e9a4b04a10b6107a13a09361