Malicious PDF — malware analysis report

Static analysis result for SHA-256 98391518e1f29ed5…

MALICIOUS

PDF

72.7 KB Created: 2021-09-11 14:09:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9be51cb811f929b82c97a6d756b6bfee SHA-1: 5644ba2ebc1634f98cdc6d629724b577e834d4d0 SHA-256: 98391518e1f29ed5dca6afa05e230cb035d955c4dcb0e51f8e597cc225ba85f5
156 Risk Score

Malware Insights

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

The PDF file contains a link farm directing users to multiple external URLs, with several hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct user-facing content, but the heuristic firings clearly point to a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://nenkin-t.com/upload_img/ck/files/bibapugowukupemusodid.pdf
    • https://unibel.pl/pliki/upload/file/35954440592.pdf
    • http://dkstores.gr/userfiles/file/18879951497.pdf
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/b0ec57e0f776b7b71468266c3786afae/bamalilus.pdf
    • http://maslag.eu/userfiles/file/xewoxakewar.pdf
    • http://palakkadtourism.in/ckfinder/userfiles/files/jezewudureriduset.pdf
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/fee71dfcec85aa8ccf751501b2eaeee9/76501084912.pdf
    • https://demo-calson.garment-pro.com/ckfinder/userfiles/files/2162477618.pdf
    • http://china-engine.net/ckfinder/userfiles/files/49913808261.pdf
    • http://paolacaone.eu/userfiles/files/jukivixoxirejugekanelitep.pdf
    • http://speckrepej.com/upload/file/wepevunimilo.pdf
    • https://gregoryshow.ru/files/file/tesugefizobugib.pdf
    • http://come2menorca.com/images/file/joloropuwamisogaxuli.pdf
    • http://risorsaterra.it/userfiles/files/27959181146.pdf
    • https://burstallconrad.com/editor_files/file/pokoga.pdf
    • http://intertribo.sk/files/5153176524.pdf
    • https://psg66.ru/admin/ckfinder/userfiles/files/3656699115.pdf
    • https://pilot-nav.com/ckfinder/userfiles/files/23330316926.pdf
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fa74913133---zonavuvubibil.pdf
    • https://ripedzn.com/app/webroot/files/fckeditor/file/56169338882.pdf
    • https://skywaytravelandholidays.com/ckfinder/userfiles/files/56316857412.pdf
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131f5ceaf5a4---31287101101.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=imagenes+de+androides+humanos
    • 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_off0000b722.bin
ce1e0a824d92c4db2754b09099c085b60b7d95382eb9595d339a21d61d3d924f
pdf-font-stream PDF embedded font (sfnt) at offset 0xB722 10600 bytes
font_01_sfnt_off0000cedf.bin
5d62debd009fc80f16c1e9fbcbeb7d0df35c0d108cbcfb9140dff8a9377a9d3d
pdf-font-stream PDF embedded font (sfnt) at offset 0xCEDF 17764 bytes
font_02_sfnt_off0000fb8c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFB8C 16792 bytes