Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac5cfcfa7329a3b4…

MALICIOUS

PDF

80.2 KB Created: 2021-09-09 06:55:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 45b817c6f855c577517cb5e385456781 SHA-1: 181a6ca797c55d9e66a46441cfc8d7d28488ed08 SHA-256: ac5cfcfa7329a3b48c97710d7fd6579160e50afde70695f92d910806cb292299
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS upload directories or appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and does not provide direct textual clues, but the heuristic firings and URL analysis point to a malicious link farm strategy.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 https://aluminiosarla.com/userfiles_arla/files/90109854104.pdf
    • https://pensiuneaselina.ro/userfiles/file/xirosukubumaxobeza.pdf
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16132c7cac43b4---66652156840.pdf
    • http://officinedesign.it/userfiles/files/vutedazaponolorebot.pdf
    • http://marikitaberbagi.com/userfiles/file/wodetobumudej.pdf
    • http://donghotam.com/luutru/files/fatotivawaxidokesabawobe.pdf
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/qc0efjoono93ar03u7cnn3jpn0/butugemagapuvokowojela.pdf
    • http://dakmoto.cz/obrazky/file/fenota.pdf
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee26e90abf---mirilelutobofofupatuni.pdf
    • http://sh-ruiyangcpa.com/userfiles/file/2021-9///2021982328152903.pdf
    • http://jolanyee.com/upload/files/202109021204226529.pdf
    • http://veoguidecostarica.com/ci/userfiles/files/xemazigejumizisilexibugov.pdf
    • http://bresky.cz/res/file/tuxigukepezedada.pdf
    • http://m-s-g.ru/userfiles/files/65315295446.pdf
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/6a76246b3d53618de8879d2852c04fb8/lamibarun.pdf
    • https://nhahangthanghuong.com/uploads/files/3961508645.pdf
    • http://www.chiringuitomediterraneo.com/ckfinder/userfiles/files/bazipimomelogise.pdf
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/c4ce27f8d30a40dafb29a364b3d8fbef/birawudoliz.pdf
    • http://reszke.pl/fckeditor/editor/filemanager/connectors/php/file/xukoronulatezif.pdf
    • http://ncteonline.com/userfiles/file/jemifalusobuwutug.pdf
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613515718b400---88353847788.pdf
    • https://artgreen.vn/attachment/files/xikipizirodumijuzufegip.pdf
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f5d6c4ae6b---2338891853.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=avatar+2+123movies
    • 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_off0000d866.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD866 16792 bytes
font_01_sfnt_off0000f07d.bin
74a4327e317761fb6ef82465f0e6c73b2f72f70a27f562f01212f70be03c2441
pdf-font-stream PDF embedded font (sfnt) at offset 0xF07D 10508 bytes
font_02_sfnt_off0001089f.bin
a7eb3d89b07f2ee7440edd3183cb62d0c51f2087277cee13c7ea789f14a0a803
pdf-font-stream PDF embedded font (sfnt) at offset 0x1089F 16680 bytes