Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa63731678f9a3bd…

MALICIOUS

PDF

81.1 KB Created: 2021-09-14 06:55:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 8547e9b8c3d06865174486e80bb7d9b9 SHA-1: 0cb9a9b7ede5932606d6815cdc0dd1acc19a0303 SHA-256: aa63731678f9a3bd1781fba20a6b902bd98fe315785640aefaa64da33211f4f2
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing embedded JavaScript, which is a common technique for delivering malicious payloads. Heuristics indicate it functions as a link farm and contains a visual download button, suggesting a phishing or malware distribution lure. The ML classifier and ClamAV detection strongly support its malicious nature, likely as a phishing or trojan delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://unixsensor.com/uploads/files/202109021347004601.pdf In PDF document text
    • http://hooleihomes.com/cms_images/file/kivuv.pdfIn PDF document text
    • http://pazzo.jp/js/upload/files/xegogarawudafasun.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f08daf3450---guxojupokisazutexatadeb.pdfIn PDF document text
    • http://learnersdigest.org/userfiles/file/gabenovukigupinotel.pdfIn PDF document text
    • http://gps-tw.com/CKEdit/upload/files/zerupejijivigapo.pdfIn PDF document text
    • http://marthomaiticherukole.com/userfiles/file/kurezasegufosoxixetaxi.pdfIn PDF document text
    • http://mim2010.ru/userfiles/file/bodusesumaranadeziwod.pdfIn PDF document text
    • http://virtualcharityevents.com/vce_cake/files/files/70109254953.pdfIn PDF document text
    • http://dayuntang.com/assets/uploads/ckedit/files/20210901192939.pdfIn PDF document text
    • http://chiangmai-esc.net/user_img/files/fodofijegonadugizusineki.pdfIn PDF document text
    • https://snqrsl.quebec/upload/editor/file/sukasupeligorabazitode.pdfIn PDF document text
    • http://charugarware.com/DEVELOPMENT/charu_garware/uploaded/userfiles/file/39625840676.pdfIn PDF document text
    • https://calson.garment-pro.com/ckfinder/userfiles/files/fesukezezifinaliwapuwe.pdfIn PDF document text
    • http://wingmanresearch.com/userfiles/files/foxulewiwezuneg.pdfIn PDF document text
    • http://huzatfokozo.hu/editor_up/58318519400.pdfIn PDF document text
    • http://xn--80aantfcaehjbxzf1m.xn--p1ai/userfiles/file/birelonebifo.pdfIn PDF document text
    • http://print-printonline.com/ckfinder/userfiles/files/9941129401.pdfIn PDF document text
    • https://anne-berger.de/sites/anne-berger.de/files/fkcfile/81856747180.pdfIn PDF document text
    • http://licausi.it/userfiles/files/tonebodunuzimo.pdfIn PDF document text
    • http://emanuelmlevin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/64300236748.pdfIn PDF document text
    • https://matricula.netlandschool.cl/files/tusevowexebevekazero.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=wrong+turn+5+480p+downloadPDF 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_off0000d305.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD305 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eb17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB17 19508 bytes
SHA-256: 45a6b088e8c0ed797fa6d605980b4f8f9e295422d678c406fd39802d6d09f149
font_02_sfnt_off00011e2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E2F 10896 bytes
SHA-256: 1913c8b4e146ae5aeeca506bfc6919b001a2cf9e2d5d1f3b96ed8dd6cbc15282