Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b9c35d857d62bd1…

MALICIOUS

PDF

82.3 KB Created: 2021-07-13 00:05:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 01640133128aeb401171ecae933b4da3 SHA-1: b9412fee0961697fba0584010e236a168b8acf22 SHA-256: 8b9c35d857d62bd11493f9ae2387fc35015f3073ec3437528b9710ad424079a6
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs and link farm patterns, suggesting it is designed to redirect users to compromised websites or phishing pages. The presence of multiple links on disposable hosting and compromised CMS uploads further supports this conclusion.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://queure.ru/uplcv?utm_term=the+fill+handle+can+be+used+to+do+which+of+the+following
    • https://endoaccessories.com/wp-content/plugins/super-forms/uploads/php/files/akumn3hnh7csege4rhbbuggfgv/65707506623.pdf
    • https://sardavetri.it/userfiles/file/37137988486.pdf
    • https://mytekas.com/UserFiles/file/94089001824.pdf
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/nv32kgdf3i3skbpeoiqc40guej/36166443080.pdf
    • http://www.cenlajobinator.com/siteuploads/editorimg/file/60685169272.pdf
    • http://adaviestransportltd.com/userfiles/file/newineruxevewe.pdf
    • http://jacksonreunion.org/clients/71346/File/zilevoborimel.pdf
    • http://garantc.ru/userfiles/file/pipivozasesarufo.pdf
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/55g2n4obkioe6iqi3214n3pvh4/1563181414.pdf
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7c7093ceee---javufupilizonofutuz.pdf
    • http://meyanko.com/userfiles/file///9424002764.pdf
    • http://midel.me/userfiles/file/18358477155.pdf
    • http://sobsai.com/ckfinder/userfiles/files/dozavedazatezixolezepu.pdf
    • https://cristiandellavedova.com/wp-content/plugins/super-forms/uploads/php/files/pk3qn9qup5k0o28cu00b3hbp94/74209901502.pdf
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607117e9b39ed---86181857794.pdf
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/16088da0a27849---12935907817.pdf
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc28b547f26---23164558214.pdf
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607e8a98429c7---64133231176.pdf
    • http://teckim.it/themes/userfiles//files/31621033169.pdf
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/d946d6635ace6f0f729408f09d955868/suvivuxosefutewijavazisow.pdf
    • https://grup-insaat.com/userfiles/file/85388381601.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_off0000dd03.bin
539891f0175ae8848cc9a377d53312ae5f89ad52b971b475b5ff0ebed2c2515f
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD03 10944 bytes
font_01_sfnt_off0000f623.bin
ef18c55f7b72ff6aca2e8b6c7350fe9ca20b8a68b5bb0d2936b0bf4f56af38ba
pdf-font-stream PDF embedded font (sfnt) at offset 0xF623 17532 bytes
font_02_sfnt_off00012394.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12394 16792 bytes