Malicious PDF — malware analysis report

Static analysis result for SHA-256 efa63cd4fd7c40f7…

MALICIOUS

PDF

71.3 KB Created: 2021-09-01 00:11:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: d93aa8297a6907a04b9a0fceb4b6f839 SHA-1: f1cb3d26a7213b5f53edf33cae4ac0b7d0b2449c SHA-256: efa63cd4fd7c40f79aafafb98962489cb3e864af9196d5aea1f063d64e1513a9
164 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, some pointing to compromised CMS uploads and disposable hosting, suggests the document is designed to redirect users to malicious sites or download further payloads. The primary attack vector is likely spearphishing attachment, with the embedded JavaScript serving as a secondary execution mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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
  • 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.
  • 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.
  • 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://agrilaui.com/userfiles/file/15330274011.pdf In PDF document text
    • https://www.tristar-technology.com/ckfinder/userfiles/files/bawekovezuboki.pdfIn PDF document text
    • http://leton.pl/userfiles/file/45293104388.pdfIn PDF document text
    • http://vuatoyen.com/uploads/userfiles/file/guzuvufokanurukevi.pdfIn PDF document text
    • http://thuaphatlailongthanh.com/upload/contentFile/minhchau/file/23213844169.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/6945ef9b33fb10a367d63b0ccc2cb377/joxez.pdfIn PDF document text
    • https://thinkhigh-tech.com/d/files/xokuzu.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1606f68fe14499---22053384941.pdfIn PDF document text
    • https://syteq-pro.com/userfiles/file/wemegibutaduserukilimix.pdfIn PDF document text
    • http://mhinflatable.com/upload/file/53468078477.pdfIn PDF document text
    • http://bukharasuwanee.com/sites/default/files/file/zuviru.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a11c229c7e3---gimuvimilisofawosuzali.pdfIn PDF document text
    • http://jimsclub.net/new/board/img_tinfo/file/20210821050403.pdfIn PDF document text
    • http://zjqzzx.com/uploadfile/file/2021081718433873499.pdfIn PDF document text
    • http://ctkupavna.ru/upload/file/zikavipegazolupebata.pdfIn PDF document text
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/4ae47ef7a81440aec9fe4f91bf9f8bb9/sixiposeximewibalaxenu.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b57fc6e1cc5---govaxerozebulasa.pdfIn PDF document text
    • http://quimis.org/js/ckfinder/userfiles/files/kimita.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c61ab1c69c8---6431255416.pdfIn PDF document text
    • http://usaoxin.com/userfiles/2021-5/file/94415228192.pdfIn PDF document text
    • https://bangprice.combangprice.com/beta/cms_image/file/81464896857.pdfIn PDF document text
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1609cffca18ce4---tagesabapezodifa.pdfIn PDF document text
    • http://ulv-fogger.es/d/files/pamavofawe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=reparation+to+the+sacred+heartPDF 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_off0000b738.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB738 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF4A 15728 bytes
SHA-256: 86439d760f36281c45b5c2806de30cfe43989de084b8ae3cc64e46dba51546d2
font_02_sfnt_off0000f755.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF755 10608 bytes
SHA-256: 596576accc776077a61e1c0f76559ec7c4cf1019d7dea318f7a801d985625e89