Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5639b71e5d11249…

MALICIOUS

PDF

75.3 KB Created: 2021-09-25 17:27:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: da6ae5f8c3859442dc3694e70acf9d04 SHA-1: 2f15413319ab70dbee0e64ba26dba92dd6333860 SHA-256: b5639b71e5d112491acf74ce34df6b169907869c645a84d0bd523687ff0ff63f
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to various websites, including those hosted on compromised CMS uploads and disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple PDF link farm heuristics reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9962

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://wintec-samu.hu/uploads/files/21124743547.pdf In PDF document text
    • http://metabolit.ru/files/file/31007309217.pdfIn PDF document text
    • https://buffinvestment.com/upload/ckfinder/files/fonal.pdfIn PDF document text
    • https://forumhrdbekasi.com/webroot/userfiles/files/wozarulolada.pdfIn PDF document text
    • https://zhansq.cn/upload/file/9025762890.pdfIn PDF document text
    • https://jjcfurnituremaker.com/userfiles/files/fiwasularugol.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/5t59eq6ro72gj88sq7agve22s3/vimuboguwotoravenoxobe.pdfIn PDF document text
    • http://kanalizace-ul.cz/userfiles/file/mazazewurividufi.pdfIn PDF document text
    • http://hidramaco.com/files/files/47138782118.pdfIn PDF document text
    • http://savytrading.com/userfiles/file/19553072137.pdfIn PDF document text
    • https://mcdelandes.ca/uploads/file/29939454614.pdfIn PDF document text
    • http://korea-seals.com/ckfinder/userfiles/files/759562246.pdfIn PDF document text
    • http://associatedreclaimed.com/userfiles/files/gogibuwusanepijopidekudo.pdfIn PDF document text
    • http://dralituncer.com/userfiles/file/91943589782.pdfIn PDF document text
    • http://freeorden.com/media/file/73300033747.pdfIn PDF document text
    • http://www.synagoge-stommeln.de/ckfinder/userfiles/files/muzerafomeka.pdfIn PDF document text
    • http://turhantur.com/turhantur/files/1938128945.pdfIn PDF document text
    • https://apotekatia.ba/fajlovi/32496692506.pdfIn PDF document text
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/3e27cf86f5313490031fb420b12499fd/vapisipidotazifisunifu.pdfIn PDF document text
    • http://autoscuolauniversale.it/userfiles/files/44753989979.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/ej5k3cede6ln3acs8qm76vgcu4/9179551284.pdfIn PDF document text
    • http://hzqzg.com/d/files/fuvapujisugexuvori.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=best+square+enix+games+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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000afd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFD3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c7e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7E5 15348 bytes
SHA-256: 77fc0890fc78673076be5e15be6f87bbea527bc815a870a07f829eba9cd9622f
font_02_sfnt_off0000ee9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE9D 16232 bytes
SHA-256: 01cd0e4798e93fb086042d610f43ddeed7bf091af48aa863f5c4a4f61b651684
font_03_sfnt_off00010477.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10477 10944 bytes
SHA-256: 89dd9e8bbd05983c8548a877804b7f253f888e071ed351c79e15a45bd746bd6a