Malicious PDF — malware analysis report

Static analysis result for SHA-256 5551dee804da36e1…

MALICIOUS

PDF

82.0 KB Created: 2021-09-07 15:19:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c1ffd3ea9af8b3acba3537ec488b499e SHA-1: 7818df9c7d8814d6fea395c0958165ed82281da1 SHA-256: 5551dee804da36e1fa0014e69d250e686183d5fc6594a194bf03b393fd1d02b2
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised websites or disposable domains, suggesting it's designed to lure users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via these links. No scripts were extracted, and the document body was unreadable, so the primary attack vector appears to be the embedded link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://uspeh-kursk.ru/ckfinder/userfiles/files/vufijuxojegotegexip.pdf
    • https://ntc-container.com/upload/files/sajupumojofupogeza.pdf
    • http://jafra-com.at/userfiles/file/gusetaguxejobo.pdf
    • http://alimentosldm.com/userfiles/file/47159314715.pdf
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/e107bbdd564c2ff630fc53bda962d076/83265731776.pdf
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/f830fb17005a8621587c0561a4693844/lerexigos.pdf
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/160a170850d73a---3342042030.pdf
    • http://narnivet.com/userfiles/files/siwavozanokisitu.pdf
    • https://tepihtrava.rs//files/35873733579.pdf
    • https://gulfb2b.com/userfiles/file/buwenapinifufomuxu.pdf
    • http://orvositudasbazis.eu/images/upload/file/gotumejafituvugized.pdf
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/1ad898b69c525a54fc97bbd55d4016c4/varanonezodavedodubabuka.pdf
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/cbq28jh20rmth5r38019tak005/25484074669.pdf
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e1bb146b03---90671179734.pdf
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076965994768---89359192580.pdf
    • http://www.kotolantopeni.cz/files/ponebet.pdf
    • https://srp-galabau-rostock.de/wp-content/plugins/super-forms/uploads/php/files/r2ivqihvkt5853ga3ag4mfjmgg/jedijekanasuzipizowome.pdf
    • http://blevy.com/ckfinder/userfiles/files/warutiga.pdf
    • http://nenorm.com/files/files/tazasibid.pdf
    • https://latework.cz/soubory/jogipibiri.pdf
    • http://logiccpacma.com/ckfinder/userfiles/files/81947844334.pdf
    • http://archiwum.wyryki.eu/admin/ckfinder/userfiles/files/suforujavivod.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=download+pdf+reader+latest+version+for+android
    • 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_off0000dbba.bin
474bf931bb1611abe811567c52b23c3fdb7acfa433a0bf5258d15618f4ac2a49
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBBA 17476 bytes
font_01_sfnt_off00010965.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10965 16792 bytes
font_02_sfnt_off0001217c.bin
0deb7d2fecdf68077e4a63177d3db8c3c712c3f359f601333f76ec5573390808
pdf-font-stream PDF embedded font (sfnt) at offset 0x1217C 10644 bytes