Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e81b3ef4777d76c…

MALICIOUS

PDF

83.4 KB Created: 2021-09-01 06:36:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-02
MD5: 35d9d7b8957e746321dc0a4d5aa5ba34 SHA-1: 7f5b1c21efc95e7f766e7e426e5a48a0b2065024 SHA-256: 4e81b3ef4777d76c71149237311328cf0b832dd80cf46e8d5e23262c8ddaacae
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 https://perfecthospital.org/FCKeditor/file/75464877656.pdf In PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c8bce98bdf2---padago.pdfIn PDF document text
    • http://kripasec.com/userfiles/file/girawotosebafon.pdfIn PDF document text
    • https://acronimocostanzo.com/userfiles/file/7923964376.pdfIn PDF document text
    • http://fitnessklub-impuls.pl/uploads/assets/file/35210761049.pdfIn PDF document text
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/16079a31ac4628---mojisututisivulaxisedi.pdfIn PDF document text
    • http://giftboxvietthuy.com/upload/ck/files/57788482886.pdfIn PDF document text
    • https://securityguardsupply.net/php/uploads/file/xirememavavesani.pdfIn PDF document text
    • https://deniz-sogutma.org/img/userfiles/file/46839186735.pdfIn PDF document text
    • http://schokobrunnen.com/idata/17314715034.pdfIn PDF document text
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f0ade817753---suzasu.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608150656c365---jodoretanu.pdfIn PDF document text
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b578ac8acfd---kemotogifonisiniviza.pdfIn PDF document text
    • https://reflexlighting.com/wp-content/plugins/super-forms/uploads/php/files/161a3c53f03d2da20d17c28e2cb371f4/58071094236.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/febelo.pdfIn PDF document text
    • https://etcbt.com/userfiles/file/mabumijedo.pdfIn PDF document text
    • http://libron.pl/fckupload/assets/file/wemajogunap.pdfIn PDF document text
    • http://raunlarose.us/wp-content/plugins/formcraft/file-upload/server/content/files/160825b26b1b58---senupetobefuwexo.pdfIn PDF document text
    • http://applexin.com/ttpsea/files/file/73541792525.pdfIn PDF document text
    • http://sanitaerprofi.ch/fckeditor/editor/images/file/71106283080.pdfIn PDF document text
    • http://hurtmar.pl/Upload/file/95955041998.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=fairy+tail+100+years+quest+65PDF link annotation
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/f3990759f68631aa2f53aa924f848bcd/51539788.pdfIn PDF document text
    • 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_off0000e0f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0F3 10688 bytes
SHA-256: c7a2aa5158d101db1622d4ac444ac8810b2fd1d6d9c816d77ae4e85e43850a5b
font_01_sfnt_off0000f9be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9BE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000111d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111D0 17428 bytes
SHA-256: cde239f6bfb1a153545ff7735ed757bbeeba70e7baf746fa6487ae9e4b465120