Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5c31a5753421744…

MALICIOUS

PDF

74.9 KB Created: 2021-06-27 10:54:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 1bdc619d82411a493d9ccb700b64a561 SHA-1: dc49de34f488622f1c45029512797badc6f2a448 SHA-256: a5c31a575342174453dc0e85a811856da7702e6c936f88755bf814c451a6ba01
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier. It contains numerous URLs pointing to compromised CMS uploads and disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The PDF structure itself does not contain readable text, but the presence of external links and the nature of the hosting indicate a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16076eac550dd6---13178862058.pdf In PDF document text
    • http://ks4073.com/file_media/file_image/file/pibewuvetapigidelatu.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c877fc592f4---97751448538.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/a786fd3da1ae33090e99736e7092261b/10161360525.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/04434d05fc90f6ff8bfe601b0362e33c/bufilixan.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/2acebc03b5841135e145e90ab62d5954/wemezukedogurivorukesej.pdfIn PDF document text
    • https://giriconsultancy.com/content_files/files/18615626554.pdfIn PDF document text
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/16080fc1d01f8a---56260352337.pdfIn PDF document text
    • http://alsumiri.net/wp-content/plugins/super-forms/uploads/php/files/d79f99941faf17951224e342db9b66dd/52574678524.pdfIn PDF document text
    • http://springswellness.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a8974e98383---dojobulirekitegafukaluwo.pdfIn PDF document text
    • https://rocksoliddesigns.biz/userfiles/file/bogufidabifemowumaliseb.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e48f89c40f---53788482024.pdfIn PDF document text
    • https://protechlighting.com/wp-content/plugins/super-forms/uploads/php/files/a355e906d68a83be532c6951238d30c4/54268662291.pdfIn PDF document text
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/d357d247c6c9e616d9077bacf60490cc/67796523725.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a415166243f---57060336787.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16096002045187---nudaguvebewogebolanepa.pdfIn PDF document text
    • https://karinbentum.nl/uploads/file/4915332533.pdfIn PDF document text
    • http://www.liveartsaskatchewan.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609874ab385f4---wagipajimixojoxanufim.pdfIn PDF document text
    • http://aunay-sous-auneau.fr/ckfinder/userfiles/files/53518075292.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/160a6c6545eda4---wuxufojovosadej.pdfIn PDF document text
    • http://arcenevents.nl/site/upload/files/48641877005.pdfIn PDF document text
    • https://euinsuti.ro/app/webroot/files/userfiles/files/90096068940.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=general+organic+chemistry+pdf+for+neetPDF 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_off0000bf5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF5C 11220 bytes
SHA-256: 2bbf1255ce292e9459c2a4644a701dc5082c536976297212f07e43fbdd1a0cb3
font_01_sfnt_off0000d940.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD940 16604 bytes
SHA-256: 70fc0b43454a84225f144c94ff9afb9761f829ba34613707cf38cff794d03b58
font_02_sfnt_off0001045e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1045E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1