Malicious PDF — malware analysis report

Static analysis result for SHA-256 52f23630de4bd8c2…

MALICIOUS

PDF

83.7 KB Created: 2021-09-18 01:00:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: a33af2b52522373947f23526b0ada2ef SHA-1: b86829cc5163189bd92de598a3fc160ad645992e SHA-256: 52f23630de4bd8c2c0a296fa6eabc4f5a2b2f806cf5ef018edf34279855c14cb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple external websites, some hosted on potentially compromised or disposable domains. The presence of numerous unknown URLs suggests an attempt to distribute phishing content or further malware payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://biothiennam.com/media/ftp/file/57961544622.pdf In PDF document text
    • https://tumsad.org/img/editor/image/file/gotebefovugij.pdfIn PDF document text
    • http://nhadatv.com/webroot/img/files/73615573377.pdfIn PDF document text
    • https://thuanxuongmonmb.com/admin/webroot/upload/image/files/wovusudepexamalex.pdfIn PDF document text
    • http://fioredda.com/userfiles/files/fufezex.pdfIn PDF document text
    • http://reversetheclocknow.com/ckfinder/userfiles/files/93349770300.pdfIn PDF document text
    • https://picinterior.com/ckfinder/userfiles/files/fenanajogulovodoxemal.pdfIn PDF document text
    • http://studiocariola.com/userfiles/files/14508033316.pdfIn PDF document text
    • http://peaceinsrilanka.lk/userfiles/file/81156493105.pdfIn PDF document text
    • http://kiddeefire.com/media/userfiles/files/6008384169.pdfIn PDF document text
    • https://hmjrgoldhockey.org/wp-content/plugins/super-forms/uploads/php/files/0a8d6a6680324c118b91c14d72313bc2/xivokuveximu.pdfIn PDF document text
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b8945742bf---24121183840.pdfIn PDF document text
    • http://pronobile.com/catalog/file/5453903057.pdfIn PDF document text
    • https://flcevent.fcu.edu.tw/plugin/ce1/ckfinder/userfiles/files/20210916001004.pdfIn PDF document text
    • https://datajournonepal.org/files/vemepipizejuwofasij.pdfIn PDF document text
    • http://cserepakcio.hu/xdata/file/82910959396.pdfIn PDF document text
    • http://rc-mst.com/mst/_upload/files/31015507270.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/28c03778b8fe5089bc5e2d4267d0818e/50598783011.pdfIn PDF document text
    • http://cephedanismani.com/images/pages/file/gozamexisisebugenike.pdfIn PDF document text
    • https://pametnidom.hr/pametne_kuce/userfiles/file/tikif.pdfIn PDF document text
    • https://ajambary.com/userfiles/file/88317862307.pdfIn PDF document text
    • https://rodolphe-blanchet.fr/Rodolphe/fckeditor/file/49194351901.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612f400fd2944---mijagugolepelewexu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=cherry+android+tv+boxPDF 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_off0000e433.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE433 17076 bytes
SHA-256: cd9f3b69c2c0ebb5770c7e59ead5dd7b4473c73477119eac17c3ee82ef5930e3
font_01_sfnt_off0001109f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1109F 10584 bytes
SHA-256: fa6eae40188cd295dc8edbb32be39a799022fde86163ed8ddb2fc418fef79221
font_02_sfnt_off000128c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128C5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1