Malicious PDF — malware analysis report

Static analysis result for SHA-256 50e6f9598332d0a0…

MALICIOUS

PDF

82.7 KB Created: 2021-09-18 22:50:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d409df82eec1dccb0bb24b845f5a1ca4 SHA-1: 4969cd6781f9b3110db1799510a05b05f4132728 SHA-256: 50e6f9598332d0a0b07423af873c39a4ef6c59f441793dadb7df2c8179f6c919
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to other PDF files, many hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of multiple external URIs and link farm heuristics supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 http://feg.vn/uploads/files/62691665430.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/683aeca600a018a870e046cf204f2286/76236803294.pdf
    • http://pasted-radio.de/web/files/50875727075.pdf
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1614242bf3a0c0---98557677500.pdf
    • http://jkbprivateiti.com/userfiles/file/17461389724.pdf
    • http://domplus.su/userfiles/files/71273322395.pdf
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144fe6c7630a---pogex.pdf
    • https://frigosztufi.ro/ckfinder/userfiles/files/79453222516.pdf
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/3f05a94e3ccde8328c479fbc15d56495/jevegogig.pdf
    • https://inprovitcentroamerica.com/ckfinder/userfiles/files/71130251855.pdf
    • http://yomamasushitogo.com/uploads/files/25740629428.pdf
    • https://christianbelieversmatrimony.com/web/christiansbelieversmatrimony/photos/ckeditor/files/90602315618.pdf
    • https://demetraproject.eu/ckfinder/userfiles/files/69570609506.pdf
    • https://12shio2.com/contents/files/30925258459.pdf
    • http://upnbkk.com/file_media/file_image/file/11240349108.pdf
    • http://vectorma.ru/uploads/assets/file/wepexakofapebotilozofik.pdf
    • http://giprozdraw.ru/ckfinder/userfiles/files/davajifajorovulafatutom.pdf
    • http://dentherapia.hu/files/file/legagowuduzatusemezavudod.pdf
    • http://ibshop.gr/uploads/_uploads/files/wozapizumugetu.pdf
    • http://stihoplet.by/upload/editor/files/kagelurimoxasafobete.pdf
    • http://hjhchem.com/upload/files/33520047418.pdf
    • https://harley.dataroom.tw/upload/files/bananalewogaz.pdf
    • http://mxag.com/upload/browse/file/kamaneremopo.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=lightroom+apk+5.2+old+version
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d561.bin
826392b8cfab3dfdcf8678fbee6e649e0293851d0f94f6d360e25ac1b7119b23
pdf-font-stream PDF embedded font (sfnt) at offset 0xD561 20224 bytes
font_01_sfnt_off000109b0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x109B0 16792 bytes
font_02_sfnt_off000121c7.bin
023b4fc2ba95e1736e45cdef6c6d09996397a98feb968b04879ac47de357334c
pdf-font-stream PDF embedded font (sfnt) at offset 0x121C7 11276 bytes