Malicious PDF — malware analysis report

Static analysis result for SHA-256 c55a3bd54f6cddee…

MALICIOUS

PDF

87.5 KB Created: 2021-07-01 18:01:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e84138fd733ca03f5d26188f9bd27fd5 SHA-1: 8669c501bf556dcc27577ba61dbceba7e4408061 SHA-256: c55a3bd54f6cddeeff2dc74a9ed2922a590876f048877a1910614d05ff08f1bc
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://cleaner.pl/userfiles/file/77448616406.pdf
    • https://noventa.cz/media/files/file/60089167517.pdf
    • http://gyobel.it/public/file/66061323533.pdf
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16087827407a47---zefugubonuvogozik.pdf
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1607187db9409e---50333261538.pdf
    • http://coffee33.ru/archive/file/12909064767.pdf
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607acefba7db3---bitom.pdf
    • https://amenagementsoleil.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac6f05f01a7---vujiduforovefinape.pdf
    • https://konferencii.ru/js/ckfinder/userfiles/files/16554236398.pdf
    • http://moriefrusca.com/userfiles/files/58800564946.pdf
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16080d0c6bce63---42654081520.pdf
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609f0887b5809---7502550584.pdf
    • http://alnahamgroup.com/userfiles/file/jubojolimekirusoji.pdf
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/09f6cead49e59910b5855461f6fb43db/46777199709.pdf
    • http://ekolojikweb.net/upld/userfiles/file/80832469233.pdf
    • http://robbinsfamilyhealthcare.com/clients/2/2c/2c787fa606fc56c3a3a24dfc5409695f/File/76655217317.pdf
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cdc0d31659b---xugexivilarivopugepigu.pdf
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/dbf9400af386cb1d0f32a517291e544a/58649356774.pdf
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/160723dae1eeb3---kitobusagupejarevajow.pdf
    • http://movementlab.dk/userfiles/file/95799972542.pdf
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/29fc671e0880103c9b5296faba285f95/3589029588.pdf
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/560beca224597244186889e867c7a701/65314338904.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=peach+and+blueberry+coffee+cake
    • 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_off0000eceb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xECEB 16792 bytes
font_01_sfnt_off00010502.bin
feb14ea138c60523a238382055e1dfc5bea167e10be6470674e3322641626cb5
pdf-font-stream PDF embedded font (sfnt) at offset 0x10502 10660 bytes
font_02_sfnt_off00011d5b.bin
4303089d3f4d33b7120216557fd7d4e4197dae795df0741acf402898425bdee0
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D5B 19472 bytes