Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3ff2a26e6ed53f5…

MALICIOUS

PDF

73.8 KB Created: 2021-09-29 06:43:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: edd3a8a396a2c43715064c4c4dfe0ea0 SHA-1: 372e3a31a3be715fcb5b3890b5928474935f85ad SHA-256: c3ff2a26e6ed53f5deade8eecb9312576cdf5b911bc8083ba89761925317fb9a
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. The document contains numerous external links, many pointing to compromised CMS upload storage and disposable hosting, suggesting a link farm designed to redirect users to malicious content. Crucially, the document includes an instruction to disable security software, a common tactic to bypass defenses before executing a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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
  • Security software disable instruction high SE_SECURITY_BYPASS
    Document instructs the user to disable antivirus or security software — unusual for ordinary documents and high-risk in an unsolicited file
  • 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://synerhu.ru/uplcv?utm_term=family+farm+seaside+hack+apk
    • https://cafesca.mx/ckfinder/userfiles/files/zufuwa.pdf
    • http://www.armstrongre.com/files/files/pedoxetanedabogesu.pdf
    • http://www.niziointerior.pl/upload/file/26040979036.pdf
    • https://luathoanghuy.com/uploads/files/sujasik.pdf
    • http://webs123.com/userfiles/file/95395722984.pdf
    • http://haciogullari.com/depo/sayfaresim/file/kikej.pdf
    • https://muratay.nl/userfiles/file/lunusikifemozedavu.pdf
    • http://www.vishalsahni.com/public/ckfinder/userfiles/files/51061502631.pdf
    • https://argentinaproduct.com/ckfinder/userfiles/files/25088924397.pdf
    • http://metrocars.london/survey/userfiles/files/83014124905.pdf
    • http://panova-art.com/files/file/nizumokiv.pdf
    • https://groupekineconcept.com/userfiles/file/47800074525.pdf
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16134327ae9013---59686416811.pdf
    • http://mkconline.com/landmark/ckfinder/userfiles/files/rozusurevikopibesolevures.pdf
    • http://kiuruvedenlukio.fi/tiedostot/file/xagolaxipurosot.pdf
    • https://ncltandatbar.com/home/ncltandat/public_html/dowalumniusa/ckfinder/userfiles/files/tavaxipunu.pdf
    • http://enovosti.info/ckfinder/userfiles/files/karunu.pdf
    • http://tokyo-sanritsu.com/userfiles/file/18155741616.pdf
    • http://patriabrno.cz/userfiles/files/52458533686.pdf
    • https://letajicikoberce.cz/userfiles/file/65524278792.pdf
    • http://styropapex.pl/userfiles/file/nopug.pdf
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/8e0g56v3s5e46c3sfo5ause5d3/notapafe.pdf
    • https://norservis.info/files/files/senagidaviwibir.pdf
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613947c6560b8---gatixevenajarunupepiwi.pdf
    • https://rt9.rspo.org/ckfinder/userfiles/files/44022423782.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_off0000b895.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB895 16792 bytes
font_01_sfnt_off0000d0ac.bin
7b22e4fe31edbf94b8209d78ef433d22b031f752205fb8c3c53e0f90a70a3440
pdf-font-stream PDF embedded font (sfnt) at offset 0xD0AC 10744 bytes
font_02_sfnt_off0000e94c.bin
44aa4416657dbfaa3664dd72b8540e8bcae41fc1e96978d2834196312528aa3f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE94C 18880 bytes