Malicious PDF — malware analysis report

Static analysis result for SHA-256 da5425858ea53486…

MALICIOUS

PDF

77.7 KB Created: 2021-09-20 01:08:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: a994c1858f5fd53b3d36aefd50bec940 SHA-1: 502e2d9ce08f56e65ee98e007a34691fc59ff921 SHA-256: da5425858ea5348600e2df42305a74b8829c5d5761c1454828cdefd8b5f638a1
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and numerous external links, including a link farm on disposable hosting, suggests the document is designed to redirect users to malicious websites or facilitate further downloads. The document body, though heavily obfuscated, originates from wkhtmltopdf, a tool often used to generate PDFs from web content, further supporting the idea of a web-based lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 https://queure.ru/uplcv?utm_term=mov+text+with+paraphrase PDF link annotation
    • https://vibangnhadat.com/uploads/files/sajudevorunefegodakadumew.pdfIn PDF document text
    • http://xn--b1agaa2anfqdp.xn--p1ai/ckfinder/userfiles/files/lefajabil.pdfIn PDF document text
    • http://autolavaggiocraparotta.it/userfiles/files/lekotufifiduburasowilesu.pdfIn PDF document text
    • http://chronocertif.com/userfiles/file/vozamozojoguja.pdfIn PDF document text
    • https://redengewinnt.com/userfiles/file/zupomegakaribogituba.pdfIn PDF document text
    • https://livermore.com/wysiwygfiles/file/35409763156.pdfIn PDF document text
    • http://ues-rb.ru/themes/ues-rb.ru/files/83837848488.pdfIn PDF document text
    • http://weilandvloeren.nl/fckimages/9446971831.pdfIn PDF document text
    • https://tanhoaphat.vn/userfiles/file/disapojuwixidapuvo.pdfIn PDF document text
    • https://cakenflowersonline.com/userfiles/file/zexemedefasarorurixilipa.pdfIn PDF document text
    • https://appvid.eus/userfiles/files/mokoteg.pdfIn PDF document text
    • https://iwanbim.iwan.co/userfiles/files/73655296472.pdfIn PDF document text
    • http://narcisse.sk/editor_uploads/files/jagaroramipokotorelejupi.pdfIn PDF document text
    • http://elliptical-trainers.ru/ckfinder/userfiles/files/neralekakeju.pdfIn PDF document text
    • http://www.saito-ken.jp/userdata/file/76248257299.pdfIn PDF document text
    • http://classiccar-jp.com/js/upload/files/21959583556.pdfIn PDF document text
    • http://geometrabottero.it/userfiles/files/5142246007.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161394d0e8e14f---39332050987.pdfIn PDF document text
    • https://sanipro.ma/app/webroot/uploaderfiles/24942301384.pdfIn PDF document text
    • https://www.antoniopopolizio.it/ckfinder/userfiles/files/1750187492.pdfIn PDF document text
    • http://fabtur.ru/upload/files/pozokolebasutujutesufer.pdfIn PDF document text
    • http://baltic-rt.ru/ckfinder/userfiles/files/95974986677.pdfIn PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/082d2bf251e25fdcca7c4a7d11ee9655/zamixifilobajomebi.pdfIn PDF document text
    • 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_off0000c917.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC917 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e12e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE12E 10444 bytes
SHA-256: b9a451fdf7a07dfa627110c87ae8f7a572b645c880c232973eaa54a86d7e8067
font_02_sfnt_off0000f921.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF921 18740 bytes
SHA-256: 1e87978960a46dbd99a6b3e927f09aab2da95eb76b0f0e1c532ff8a6440f9688