Malicious PDF — malware analysis report

Static analysis result for SHA-256 571cf81b391aeb24…

MALICIOUS

PDF

77.8 KB Created: 2021-08-22 02:16:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1613dfe8722677a70da30014aa343da5 SHA-1: 374c0e0241893359a084bfe8f06370dae4931855 SHA-256: 571cf81b391aeb24211b8501747550d5170eda45fa1d75f99ea16d0eabbb059d
156 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier. It contains numerous links, many pointing to compromised WordPress upload directories, suggesting it functions as a link farm to distribute malicious content. The presence of multiple external URIs and a link farm heuristic indicates an attempt to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9932

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://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608027bd4ab9f---22906517007.pdf In PDF document text
    • http://cfh2.com/clients/d/d2/d2a7b52150a7a947468b52e9b7560e3c/File/22811800592.pdfIn PDF document text
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607789a7c993f---64019114542.pdfIn PDF document text
    • https://wonkingchina.com/d/files/navivof.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1607a6fe958bf1---batonorapubidofebeziwowaz.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/seminete.pdfIn PDF document text
    • https://songhongresort.com/img/files/jokovokumomulezozok.pdfIn PDF document text
    • http://meyergarden.com/ckfinder/userfiles/files/13468776652.pdfIn PDF document text
    • https://partnyor.az/userfiles/file/fonukufivevujogajekorola.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b99ac60e59f---31480393268.pdfIn PDF document text
    • http://hoondb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607634fd9b923---lagesuku.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610342c2e9082---zanoruzesininisu.pdfIn PDF document text
    • http://fw-simple.com/uploads/files/sujinanuzikofojotopepaf.pdfIn PDF document text
    • http://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e6c0c8b62a9---14808252639.pdfIn PDF document text
    • http://nowator-zpu.pl/userfiles/file/gemegaxamepuxumog.pdfIn PDF document text
    • https://hostingalani.com/calisma2/files/uploads/68105640655.pdfIn PDF document text
    • http://anhuishangbiao.com/upload_fck/file/2021-4-30/20210430083724660853.pdfIn PDF document text
    • http://apsara.ru/userfiles/file/vixexigijiruwukiroxudu.pdfIn PDF document text
    • http://hb1004.com/userData/board/file/jarofinibuvewem.pdfIn PDF document text
    • http://salon-urody-bellis.pl/images/file/kapim.pdfIn PDF document text
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/3f36a73311fbc7f960ec9bbfafc30c85/68078178616.pdfIn PDF document text
    • http://newtrierreunion1962.com/clients/6/64/64567561842b0bbd40b956adda0282a7/File/suvobe.pdfIn PDF document text
    • http://jcon-aps.dk/userfiles/file/76616586845.pdfIn PDF document text
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160fe474eb89fe---2591417416.pdfIn PDF document text
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/40f8c2b421b70148626598ea62c51ae8/gufujefoleravo.pdfIn PDF document text
    • http://www.esthemed.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160850d3525bf4---mibikimusujuroxosetekab.pdfIn PDF document text
    • http://tachikawa-derma.biz/ckfinder/userfiles/files/96512480807.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/2a86a7bb8ded14cc8fee80725df046c6/fojoziwemiwedelexawikili.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=how+to+get+a+certificate+of+servicePDF 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_off0000ceec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEEC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e6fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6FE 16128 bytes
SHA-256: 08462e164991fe63788196f815428a0125ac3e2e0d3d769803a657b681c16cd5
font_02_sfnt_off00011066.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11066 10504 bytes
SHA-256: 441e1932a805394c64259d58ab60955112e412201666f5b21f187ffe5e1e0aff