Malicious PDF — malware analysis report

Static analysis result for SHA-256 af58ab9871f88370…

MALICIOUS

PDF

82.5 KB Created: 2021-09-19 09:25:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: cc52733b15386634a314c83b510e1035 SHA-1: 1359cbab7c4766878da32f1bf888b97ca18f8c43 SHA-256: af58ab9871f88370325d5c69ad49abfea57527679ed2475bc794bc944ff3aff9
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file containing embedded JavaScript, which is a common technique for executing malicious code. It also features a large number of external links, many of which point to compromised websites or disposable hosting, suggesting a phishing or credential harvesting campaign. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • 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 http://flamefitnessstudio.com/cewit/images/file/12848945568.pdf In PDF document text
    • http://bestofbeer.ru/ckfinder/userfiles/files/basefirapekiziviw.pdfIn PDF document text
    • http://uro-medical.pl/zdjecia/fotki/file/48367000466.pdfIn PDF document text
    • https://dbjadow.pl/attachments/file/kixakizepurikiko.pdfIn PDF document text
    • http://iuoooo.com/filespath/files/20210831233119.pdfIn PDF document text
    • http://brava-ekb.ru/userfiles/file/7298759800.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/e63e8faf976a7f5c5553c72ad75a25b7/7687003631.pdfIn PDF document text
    • https://cualuoihoanmy.com/uploads/userfiles/file/25874391138.pdfIn PDF document text
    • http://szolnokepul.hu/userfiles/file/jafugajobakiniwusuna.pdfIn PDF document text
    • http://lixupeng.com/uploads/files/kogamubaf.pdfIn PDF document text
    • http://machin.kr/userData/board/file/85884559653.pdfIn PDF document text
    • http://mastrodibaglio.it/userfiles/files/23499986570.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613418c7b46e2---kojasuzapo.pdfIn PDF document text
    • http://amkchem.com/upload/files/13159526171.pdfIn PDF document text
    • https://egf.tw/test2/images/file/87509233888.pdfIn PDF document text
    • http://nhasachconggiao.com/luutru/files/mexojo.pdfIn PDF document text
    • http://canavesiobruno-architetti.it/userfiles/files/nafofuwodozixipibo.pdfIn PDF document text
    • https://editora-arara-azul.com.br/site/admin/ckfinder/userfiles/files/98488390351.pdfIn PDF document text
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/32de4c4453a78bbf7e6ac6b634096093/nuwarikulid.pdfIn PDF document text
    • http://mmsmarin.com/imgimage/file/lafow.pdfIn PDF document text
    • http://www.phsdcenter.com/temp/js/ckfinder/userfiles/files/dogabegoguloxemubavaz.pdfIn PDF document text
    • https://henseltech.cz/userfiles/file/8666102343.pdfIn PDF document text
    • https://magerp.org/upload/files/42678292584.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=best+app+to+recover+deleted+contactsPDF 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_off0000de7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE7D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f694.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF694 10532 bytes
SHA-256: 3db83be591523c70da78d2810ba21e0458997cb3cb13afd3172545045eba4c56
font_02_sfnt_off00010ec6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EC6 17396 bytes
SHA-256: 82935f5b6d981134dab3458ab0188c6044c3bcf73b9defdc93485ce92087e909