Malicious PDF — malware analysis report

Static analysis result for SHA-256 e39ceb2ec2531c23…

MALICIOUS

PDF

78.8 KB Created: 2021-09-22 09:27:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 25ed1a787ed685fd184f4e0b683ddd67 SHA-1: 2b7cc90c74dccfa8044925edd58c0b2aaa1ebf4a SHA-256: e39ceb2ec2531c2394d0c4740ce18c40e0cecd65792c3c068d08f5356e3f8e45
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to potentially compromised or disposable hosting sites. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM firings supports this, suggesting an attempt to distribute malicious content or phish credentials through a network of linked documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 6

  • 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.
  • 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://i-try.tw/upfile/files/2021/09/17/wedozonibawugoto.pdf In PDF document text
    • http://files.ibiza-ferien.de/file/95408709244.pdfIn PDF document text
    • https://biharlokmanch.org/userfiles/file/febim.pdfIn PDF document text
    • http://zpkprzemysl.pl/ckfinder/userfiles/files/45232465222.pdfIn PDF document text
    • http://ebonit.light.bg/includes/libs/ckfinder/userfiles/files/54234964705.pdfIn PDF document text
    • http://yeosingol.com/FileData/ckfinder/files/20210918_9A813A6592D64B12.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/161419917e4aac---4519824995.pdfIn PDF document text
    • http://weilandvloeren.nl/fckimages/54931722440.pdfIn PDF document text
    • http://natpuedu.in/userfiles/file/98879614706.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161440bd00f382---17103625857.pdfIn PDF document text
    • http://studiotecnicobonoli.com/userfiles/files/ferolasor.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/drke1f2dj0g5bc61c0gbqqmeq3/jadakifu.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/1614984db453ea---febobuzagapusak.pdfIn PDF document text
    • http://cuboni.com/uploadfile/hong202109060857397710.pdfIn PDF document text
    • https://lacgl.org/upload/editor/file/sogopuvukizojokovo.pdfIn PDF document text
    • http://rinsacars.com/files/others/xikiwedake.pdfIn PDF document text
    • https://stancijanegrin.com/UserFiles/files/66446110742.pdfIn PDF document text
    • https://cncunse.com/d/files/55272594958.pdfIn PDF document text
    • https://smartech.lv/sites/smartech/uploads/documents/files/zobeji.pdfIn PDF document text
    • http://kledingindex.nl/images/uploads/tiravorawexixa.pdfIn PDF document text
    • http://sinice-rasy.cz/files/file/noleporebisas.pdfIn PDF document text
    • http://purel-biopharm.com/upload/files/89865512637.pdfIn PDF document text
    • http://monteconsultants.com/image/upload/File/85611596968.pdfIn PDF document text
    • http://dc-a0dcf319a153.breakthroughsport.com/userfiles/files/42190707826.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=gmail+untuk+androidPDF 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_off0000d14a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD14A 17640 bytes
SHA-256: 3e3d28d7945a6ee4455b67d1f0da3460c55852ee3132b25b10a3e8b130320cd3
font_01_sfnt_off0000fecc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFECC 10340 bytes
SHA-256: 14978602ec75e1c887c4ea9b0f126d65f602fb3c96a8b079ef6f5b17ac673f4f
font_02_sfnt_off0001160d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1160D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1