Malicious PDF — malware analysis report

Static analysis result for SHA-256 6f6816564a1ae6e5…

MALICIOUS

PDF

81.5 KB Created: 2021-09-12 13:32:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ab3c0aac3374314c9c9fde811a694d0d SHA-1: 750c9320412a29fcc58562336e6f29426eb32761 SHA-256: 6f6816564a1ae6e52ac7402cad3bed7790024c05b434d8672bf596472bd1e4be
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://m-astar.com/UserFiles/files/43026325946.pdf
    • http://ipsaix.com/ckeditor/ckfinder/userfiles/files/tisadoziwosesodefu.pdf
    • http://eotp.info/sites/default/files/fck/file/62882420491.pdf
    • https://cornwallstaffagency.com/userfiles/file/sefin.pdf
    • http://footstepfloor.com/upfiles/files/92444810900.pdf
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a810a20f37---7258696226.pdf
    • https://ajansnigde.com/resimler/files/bafap.pdf
    • http://ruihuitax.com/files/file/62168450031.pdf
    • http://dotbamboo.com/file_media/file_image/file/suwafutuvuped.pdf
    • https://www.hkfew.org.hk/ckfinder/userfiles/files/wozufesagepefokabexepuzig.pdf
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/50393086f958871ed2610dd4adc341b6/vulomupemariwojotup.pdf
    • https://episcopiaoradiei.ro/files/xiwilinedaxewe.pdf
    • http://velomagazin.hu/UserFiles/file/17639302842.pdf
    • http://maristaslardero.es/userfiles/file/mofiwujusu.pdf
    • http://sz-nuoyi.com/Upload/file/2021090622575428212.pdf
    • http://epoch-making.jp/js/upload/files/kipamelukuzowagukapi.pdf
    • http://2ds-creations.fr/userfiles/file/84117334973.pdf
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613abb68363f7---pibaw.pdf
    • http://andreuma.madteam.net/ckfinder/userfiles/files/gasajusow.pdf
    • https://kotypsy.pl/ckfinder/userfiles/files/75334686491.pdf
    • https://ckmandarin.com/uploads/29435061807.pdf
    • http://reginahajo.hu/_user/file/tevapiv.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=cool+launcher+pro+apk
    • 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_off0000d8b6.bin
188ea8b151849367ebd57b932b4c4afbb029323cc9184ff137c21e3860eef424
pdf-font-stream PDF embedded font (sfnt) at offset 0xD8B6 18920 bytes
font_01_sfnt_off000109bb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x109BB 16792 bytes
font_02_sfnt_off000121d2.bin
b7fca1154dad6e644c7f89f3f0d32e09ee08f477dba3c6016b7a972152347459
pdf-font-stream PDF embedded font (sfnt) at offset 0x121D2 10336 bytes