Malicious PDF — malware analysis report

Static analysis result for SHA-256 d74755b33ac048f8…

MALICIOUS

PDF

72.9 KB Created: 2021-09-09 06:09:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: dbab0625e6ff3fca9a511c13e62aee99 SHA-1: 9fe8fc31b53783b32521de1a7519af0a210b58f9 SHA-256: d74755b33ac048f8ecc03c65539065d265894c6212051fa7b16bd201dccaf029
142 Risk Score

Malware Insights

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

The sample is a PDF containing embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities to execute arbitrary code. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely downloads and executes a second-stage payload from one of the numerous external URLs found within the document, aligning with a phishing or malware delivery attack pattern.

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://thuduchouse.vn/pics/file/misilijutafewijawedena.pdf In PDF document text
    • https://ciar.vn/uploads/image/files/28762383821.pdfIn PDF document text
    • http://fobas.cz/userfiles/file/98456444831.pdfIn PDF document text
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/edcc7a9957c0268084fcb57e52522aec/719350920.pdfIn PDF document text
    • https://vsevolozhsk.mebel18.com/uploads/files/vomagexanidasuxetor.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/dka91bhf19tr6lum7n45igp606/38669682477.pdfIn PDF document text
    • https://ebal.ro/app/webroot/files/userfiles/files/32272747662.pdfIn PDF document text
    • http://xn----7sbndn5at.xn--p1ai/uploads/files/dobupuripazalafowoviro.pdfIn PDF document text
    • http://www.520amis.com/upload/files/bovuwawefafavixivuna.pdfIn PDF document text
    • https://smilaxlabs.com/userfiles/files/majan.pdfIn PDF document text
    • http://signauction.net/userfiles/file/33415735640.pdfIn PDF document text
    • https://betamachinery.sa/other_files/File/kifevenavexemakuw.pdfIn PDF document text
    • https://dorfadvertising.com/ckfinder/userfiles/files/54491783686.pdfIn PDF document text
    • https://24emk.ru/ckfinder/userfiles/files/92687238019.pdfIn PDF document text
    • http://pibar.tw/uploads/files/202109030911386381.pdfIn PDF document text
    • https://kligi.viart.lt/ckfinder/userfiles/files/38237936000.pdfIn PDF document text
    • http://ms-beauty.com/ckfinder/userfiles/files/zufipowawur.pdfIn PDF document text
    • http://ecole-belair.com/ecole/file/1445374011.pdfIn PDF document text
    • https://leciv.fr/uploads/FCK_files/file/todinugoso.pdfIn PDF document text
    • http://tlxzkj.com/uploads/file/011117573565.pdfIn PDF document text
    • https://saintarseny.ca/sites/saintarseny.ca/files/file/24885940481.pdfIn PDF document text
    • http://classicalgardenornaments.com/uplds/file/zonesenuzo.pdfIn PDF document text
    • https://clubesolbra.com/uploads/files/7398303701.pdfIn PDF document text
    • https://www.rongoldmanlaw.com/system/js/back/ckfinder/userfiles/files/70930494929.pdfIn PDF document text
    • https://aquaprosmart.com/userfiles/files/29954266637.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=phantom+forces+script+guiPDF 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_off0000b7a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7A2 17508 bytes
SHA-256: b7ac4a88e2e8952b4f049c5181a4aa93d02d3c5cdd014f867c1eb13d715ca0ab
font_01_sfnt_off0000e48a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE48A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fca1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCA1 10984 bytes
SHA-256: cc160f35b233aea890a7702aaeb34ce18a3f411ca915be50ea161c067a1886fa