Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac4af73d9f7d65f3…

MALICIOUS

PDF

91.1 KB Created: 2021-07-03 17:54:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 20d0d316df20556f71ecf944e1dd9e02 SHA-1: db5db127769e6064a30453b35e9a839cd574cbd0 SHA-256: ac4af73d9f7d65f3b3d12b3d4b1fd432974d88f897694c1b42d274012e7eb6ac
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised WordPress upload locations and disposable hosting sites. The embedded URLs likely serve to distribute further malicious content or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://cambridgekapurthala.com/damana/userfiles/file/37437706669.pdf In PDF document text
    • http://ajivikafinance.com/userfiles/file/vekiziris.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/mfuff684osmlhte6tmun08v656/zuturafevi.pdfIn PDF document text
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/e2f91a8405691c9355f9dd91aa411818/rufegepu.pdfIn PDF document text
    • http://workprohealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e222ebcc4d---46419675711.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a676c5acf7a---34538669108.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1606f47c5a136d---zifuxagore.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d67b6edfac4---sejebazazuja.pdfIn PDF document text
    • http://abwlargo.com/uploads/files/fidusixeninajuvu.pdfIn PDF document text
    • https://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/aed801ae16f02e6901ae835c88a579d5/9711158291.pdfIn PDF document text
    • https://ukdirectremovals.com/wp-content/plugins/super-forms/uploads/php/files/0115a4bcaf35f2aae5c7850bd2c9c445/zonukopewojefupakumaxo.pdfIn PDF document text
    • http://el-master.ru/userfiles/file/xuwejikujowa.pdfIn PDF document text
    • http://szsahsh.com/uploads/files/reduguratigezim.pdfIn PDF document text
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/hc49ovck9u34emkgcccf9dn8gn/naxuzorusinofukefidebi.pdfIn PDF document text
    • https://tractorpulling-emmeloord.nl/upload/file/tezipunovifexo.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/160b84b10beac5---79425418530.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/2682be191a1b6b1889185272e793beac/mikizakodurimegifejo.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/16085fd50df872---rofenidubesuxugotilu.pdfIn PDF document text
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/0841d1277458de6ff89453d029fb8228/somasegakojonamoxabiw.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/6391b0072d1c1ebffd986c8cf6216540/bisajemepoboluvowepeber.pdfIn PDF document text
    • https://musikkursus.dk/userfiles/file/69450384204.pdfIn PDF document text
    • https://www.lindopoint.it/wp-content/plugins/super-forms/uploads/php/files/dbb7f5f53c5db4a788ef5a6d5414485d/xusene.pdfIn PDF document text
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/160a2d1a05380a---kumekipaxifarem.pdfIn PDF document text
    • https://edoxmarketing.com/wp-content/plugins/super-forms/uploads/php/files/91vhva9gnrj4n80cmnuq3aiuma/91163986106.pdfIn PDF document text
    • http://epoxidice.ro/mm/file/44011622342.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=b2799+engine+immobilizer+system+malfunctionPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fda0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDA0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000115b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115B2 17364 bytes
SHA-256: 1dd7a606d3801e6141ade128a1fced337d047a96e1bfb7e14922dc77308eca37
font_02_sfnt_off00014345.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14345 11484 bytes
SHA-256: 221f6b62858db9a604a0e6e6c7c42a8dfe20c581b39282ee1795d05eb0d77ca3