Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c163f8c2831fe21…

MALICIOUS

PDF

97.3 KB Created: 2021-07-01 09:53:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3a91c65b012432eb747b745cc7e7b9e6 SHA-1: 3dba0fc3e99b3bd9ad01bea09deadf0f9a4ebe7f SHA-256: 4c163f8c2831fe21e8378987dac0416bdd1f91401be996f16c3b6ab3585c280c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a link farm that directs users to multiple external websites, some of which are hosted on compromised CMS upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable, limiting the analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9822

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://okfilm.kr/userData/board/file/fukuf.pdf
    • https://sharadsangam.org/UserFilesTwo/file/miduwiviveg.pdf
    • http://kme-kme.cz/files/file/dakozubukixe.pdf
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/af9fekvhp1f1mldbiogmkgqnuu/zufarenefu.pdf
    • http://lowry-averyreunion.com/clients/c/c0/c0e4e7922159a76f956c19110b7bfeb7/File/mebovizidapifa.pdf
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f16c3abb0d---80154064437.pdf
    • http://kristenpell.com/userfiles/files/vonetonexozo.pdf
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/5734ae0e80374ad0ed43715505940512/muwixaxamubuvo.pdf
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/b45b6a7229033fe5a5937bb22d6ad1e7/duwidurafonomovovalo.pdf
    • https://messianic.live/wp-content/plugins/super-forms/uploads/php/files/651fe71d02c4d26903699425409069ca/lowepuz.pdf
    • http://geobigoni.it/userfiles/files/21428042525.pdf
    • http://blueyee.com/upload/file/26035456375.pdf
    • https://signaturetowerpune.com/wp-content/plugins/super-forms/uploads/php/files/gq395blo2v2r5h508eptqh8qh2/tutizodibisovesimogatutiw.pdf
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/1810gr5rneoelgua7aih3kff81/44714285266.pdf
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2c17077a50---diwoni.pdf
    • http://geodeslaboratori.eu/userfiles/files/39654475137.pdf
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608cfbbaeb5e3---99120384671.pdf
    • https://licorne-hotel-restaurant.com/userfiles/file/68679107802.pdf
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16072da0804480---wunilimipikokoduwisofuj.pdf
    • https://parc-hotel.info/file/fidoju.pdf
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160ac7256a603a---senojagesijebifato.pdf
    • https://www.kadeavenue.com/wp-content/plugins/super-forms/uploads/php/files/969ffeaf6274eaf9754fdf1469e3e775/polutaxupiza.pdf
    • http://www.afamaresme.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608098aeb8fa6---fovoropipekanufe.pdf
    • https://daotaolaixesontay.com/uploads/file/budusamisuj.pdf
    • https://detmers-kontejner.hr/files/85415200560.pdf
    • http://innospectrum.eu/hirlevel/file/48706339064.pdf
    • https://fedico.ca/upload/editor/file/70210369971.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=has+vs+have+been
    • 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_off00011006.bin
cfbdefc76220829d022a7666327060aaf71756b90ae6fa62f9cac38946f53a9c
pdf-font-stream PDF embedded font (sfnt) at offset 0x11006 27032 bytes
font_01_sfnt_off0001489b.bin
5a8a186ad9d07b7565399ef4955cac1e8c5b9117abf08b266183020645520487
pdf-font-stream PDF embedded font (sfnt) at offset 0x1489B 9948 bytes
font_02_sfnt_off00015e7d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15E7D 16792 bytes