Malicious PDF — malware analysis report

Static analysis result for SHA-256 27c915b963aa1ec5…

MALICIOUS

PDF

79.5 KB Created: 2021-09-15 13:50:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2cd5b100bb13d59cc9e34f9108b0e277 SHA-1: 372e0162acc6f2974ef68a8f6cda5693cc2c6512 SHA-256: 27c915b963aa1ec5bb409aa23c73a4c8ce54d90b38efc37a48aa3dcb16eb56bb
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are associated with link farms and disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a malicious document, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://krisoc.ru/uplcv?utm_term=real+drum+apk+free+download
    • http://thietbibepnhahang.net/media/files/xamirilubavoxutenof.pdf
    • https://konyaalotaksi.com/userfiles/file/dazugemusupamonulovuvijis.pdf
    • http://brandiassociati.it/userfiles/file/64294921390.pdf
    • http://majorpropertygroup.com/userfiles/files/gunosu.pdf
    • https://baoholaodong24.com/userfiles/file/31236812212.pdf
    • http://onelove.cz/file/xusugeku.pdf
    • http://ctyrkolky-gamax.cz/data/dokumenty/zajozurarizusugofirugesu.pdf
    • http://musicandyouapp.com/webupload/editorimg/files/waxerajinubejubabizibup.pdf
    • http://askaudit.ru/price/45257164878.pdf
    • https://apc-algercentre.dz/ckfinder/userfiles/files/negudefojexegasabo.pdf
    • http://combatkuntao.com/ckeditor/ckfinder/userfiles/files/mumuvosexewen.pdf
    • https://stgeorgedentalcare.in/ckfinder/userfiles/files/luwejozawo.pdf
    • http://ms-beauty.com/ckfinder/userfiles/files/99746979247.pdf
    • https://resulgame.com/calisma2/files/uploads/risavegikitelilolukudob.pdf
    • https://mgrenginiai.lt/ckfinder/userfiles/files/rugawiditafijogamuxuxi.pdf
    • http://stlnsk.ru/uploads/file/5818234852.pdf
    • http://unibox.lv/files/text/2736691741.pdf
    • https://incoyun.com/calisma2/files/uploads/5659255787.pdf
    • http://xn--nellieskche-0hb.de/userfiles/file/26389602530.pdf
    • http://sushiosushi.com/uploads/files/gosejuperuwobugulokejemip.pdf
    • https://bisleri.genefied.co/ckfinder/userfiles/files/62365997051.pdf
    • https://gionggiacam.com/ckfinder/userfiles/files/58217397567.pdf
    • https://askisan.com/upload/ckfinder/files/35658219085.pdf
    • http://centralgiving.com/media/userfiles/file/jozirozos.pdf
    • 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_off0000d171.bin
b520f8a14f9fa0fc9c01807d19c06e769a8c74b4b9b66c167a4815176e047fc7
pdf-font-stream PDF embedded font (sfnt) at offset 0xD171 17800 bytes
font_01_sfnt_off0000ffda.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFDA 16792 bytes
font_02_sfnt_off000117f1.bin
a1930cf913803ad3381a3953640904405cfeb9336086010cd12312deaed68f17
pdf-font-stream PDF embedded font (sfnt) at offset 0x117F1 10624 bytes