Malicious PDF — malware analysis report

Static analysis result for SHA-256 a51b9f8999a91fc1…

MALICIOUS

PDF

84.6 KB Created: 2021-07-02 14:46:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5f31cc386b421345ccc80b82467c1370 SHA-1: 1b192d1dd8c25a6b6ca4a0e0815e0f2ba2ce17aa SHA-256: a51b9f8999a91fc1e26e9b5b19bee1326b5b34f0b38e6ea5f099e07f6cd38ee2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links, many of which point to compromised WordPress sites and are structured as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or directing users to malicious content. The presence of external URIs and link farms suggests an attempt to lure users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://xn--clinicaquirogavilario-vbc.com/wp-content/plugins/super-forms/uploads/php/files/afa4h922bdfduo97e67sfm43s2/5592774000.pdf
    • http://automsystem.com/UploadFile/file/20210517114533237.pdf
    • http://holidayinntorino.com/userfiles/files/tufitap.pdf
    • http://villa-carlshorst.de/sites/default/files/file/35704228535.pdf
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/l6n825mivsk3nkkjqfrve29hd6/jalinufijotipuxeg.pdf
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/b8293f2ed31c19f526cf3a253c8a5179/69168822522.pdf
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/d9bd3d0d9db277218342d2a05c89498d/27880252152.pdf
    • http://desushibar.com/userfiles/file/73443188127.pdf
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c279e0e7d4c---xizisokosupurebojivamefa.pdf
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/e6d168e84220a5ca679f78a04eb587db/lasafejugujufakat.pdf
    • http://rollfactorytogo.com/uploads/files/buwazesisorivesoxok.pdf
    • https://sasalidayanisma.org/uploads/file/mumiz.pdf
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bc1159b70e---460831885.pdf
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/1607ac89b3a7c0---gavovowokabexesirapudamu.pdf
    • https://salubrismd.com/wp-content/plugins/super-forms/uploads/php/files/59f2411d8f4ededa03619b85653f4d02/47085403681.pdf
    • http://ahdongjiu.com/upload_fck/file/2021-4-29/20210429030026570142.pdf
    • https://www.basur-tedavisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078278aeb043---86861643486.pdf
    • http://3dprofi.net/images/uploads/file/garitesakaziputinegunena.pdf
    • https://www.napariverinn.com/wp-content/plugins/super-forms/uploads/php/files/8f9b02cf2c68d5d010cc424bf21a1c4e/xakomovejemekexadepanat.pdf
    • http://archi1919.com/smlclub-files/file/zujoxolixabeneluwu.pdf
    • http://kapelski.pl/userfiles/file/bovup.pdf
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/jseuamkr9i1v9k6h15k5vt0vf3/ruviwemi.pdf
    • http://majorpropertygroup.com/userfiles/files/monudadipakugomutubesesa.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=the+oxford+handbook+of+american+public+opinion+and+the+media
    • 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_off0000e946.bin
cdaf288e5e568441143a5b1cd43027e60e03f377b939640949726f63d6163e1f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE946 11112 bytes
font_01_sfnt_off000102cf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x102CF 16792 bytes
font_02_sfnt_off00011ae1.bin
3f0b6a42b972c5baeccfb92da52018ff3a5f075cab6e25314e3de11af9196619
pdf-font-stream PDF embedded font (sfnt) at offset 0x11AE1 16232 bytes