Malicious PDF — malware analysis report

Static analysis result for SHA-256 bd4b1439b6a05792…

MALICIOUS

PDF

71.5 KB Created: 2021-10-11 00:37:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 12e0dc90c043e8ce1cf8501d80308712 SHA-1: e1175e3d8fb14c82b5e50228910b0e7f64cd087f SHA-256: bd4b1439b6a05792cc557e0d2a56117838ae2e750c46f13c4455bb33bc75f662
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm hosted on compromised WordPress sites, suggesting a phishing or redirection attempt. The presence of numerous unknown URLs further supports this, as they likely serve as part of the malicious infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • 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.
  • 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://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/161409e3b3512d---97143025388.pdf In PDF document text
    • http://zlhk.ru/upload_picture/file/66742171486.pdfIn PDF document text
    • http://sanga.asia/userData/board/file/biluraweg.pdfIn PDF document text
    • http://rbtyutj01.com/userfiles/files/fenoxidakogenefana.pdfIn PDF document text
    • https://ww150002.linebot.net/upfile/files/20210922165614.pdfIn PDF document text
    • http://security-m.jp/tool/images/file/18077762592.pdfIn PDF document text
    • https://parfumzone.ro/files/file/molefijimode.pdfIn PDF document text
    • https://lacausedeslivres.com/userfiles/file/ritusez.pdfIn PDF document text
    • http://siciny.eu/userfiles/file/68355277026.pdfIn PDF document text
    • http://arc-en-cielproduce.com/ckfinder/userfiles/files/dusik.pdfIn PDF document text
    • https://ags-car.60km.com/upload/files/tigoxekegaketafow.pdfIn PDF document text
    • http://elektromig.pl/userfiles/file/banekibakumurema.pdfIn PDF document text
    • https://specializedfacilitymgt.com/public_html/userfiles/file/30511068327.pdfIn PDF document text
    • https://yocarbroker.com/upload/ckfinder/files/69512793681.pdfIn PDF document text
    • http://reckdance.pl/userfiles/file/galixelebojaneronetam.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/3f1eaad3d6d06852bfe3d56b2941fc43/18222570633.pdfIn PDF document text
    • https://kalendarz.probik.pl/fckeditor/userfiles/file/88495624201.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/161600d82c5e13---tedojezixuxajemafifibitid.pdfIn PDF document text
    • http://eternaseguros.net/files/files/40268264011.pdfIn PDF document text
    • https://behbehaniprojects.com/uploads/files/80158905992.pdfIn PDF document text
    • http://northcity.rs/slike/files/bowawolixi.pdfIn PDF document text
    • http://ceraunavoltapizzeria.it/userfiles/files/77488014207.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/novogaxexuw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=sek+currency+to+euroPDF 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_off0000b7e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7E3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cffa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFFA 10136 bytes
SHA-256: 8c000af77fcaaff0744fa16837bc1312d9ea22c66129c1ea71c98c556d3e3d4f
font_02_sfnt_off0000e6d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6D3 16228 bytes
SHA-256: 0a4b234f118b0a8ed697d4aa2237ef14aedd9b19401b00c4b37ae2f69ec8f956