Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8c748b1583c1f55…

MALICIOUS

PDF

79.5 KB Created: 2021-09-07 01:44:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4983448fca36ec1a4c4b85f6fc1886a0 SHA-1: 23d56d58c6109e9f9bc95008f4fcd4f038a2ae22 SHA-256: c8c748b1583c1f55835eeb460813434b96fb6a4ebb86aeefad7a9c8ab9063144
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised websites or disposable hosting, indicating a link farm designed for malicious redirection. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated, preventing a clear understanding of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://narnivet.com/userfiles/files/binolugizudemunabo.pdf In PDF document text
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/1607b7ccb21052---90117761621.pdfIn PDF document text
    • http://siltherm.com/ckfinder/userfiles/files/gizot.pdfIn PDF document text
    • https://menu2uplus.com/images/file/lufodixefedinavasafeja.pdfIn PDF document text
    • https://nezrenweb.com/calisma2/files/uploads/62512310308.pdfIn PDF document text
    • http://alarcon-v.com/editor_upload_image/file/3308706742.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7c2e4b5399---98812767008.pdfIn PDF document text
    • http://sysquare.com/UserFiles/files/jozuvulozunasagezurema.pdfIn PDF document text
    • http://www.astmalek.cz/obrazky/file/zogevanarebo.pdfIn PDF document text
    • https://stollerco.com/testingsites/advantage_aviation/assets/media/file/65217597054.pdfIn PDF document text
    • http://steffis-strassladen.de/userfiles/file/gekupulo.pdfIn PDF document text
    • http://immodraft.nrw/images/architekten_agentur_images_/file/48368223389.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1609f8e94975cf---lokixoxegibajulonosuxeto.pdfIn PDF document text
    • http://makesrealsense.com/ckfinder/userfiles/files/xaxukodasi.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/f4cf5787a33491175f71a757b134ef19/3898451156.pdfIn PDF document text
    • http://sure2trips.com/bot/ckfinder/uf/files/mopukefapadodapob.pdfIn PDF document text
    • http://aktifithalat.com/resimlerfiles/nowufavikodosolabopeteva.pdfIn PDF document text
    • https://amursvoidom.ru/media/files/refebobelugegakosodika.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160b103bd1f9b8---peroterosorusasowobofit.pdfIn PDF document text
    • http://thaoduocquyhiem.com/userfiles/image/file/xijudogi.pdfIn PDF document text
    • http://xsjprinter.com/d/files/jawagagugef.pdfIn PDF document text
    • http://laboratoriodiprogettazione-ve.it/userfiles/files/63210346749.pdfIn PDF document text
    • https://ddshower.com/ckfinder/userfiles/files/lavewopegezumolox.pdfIn PDF document text
    • https://habibitours.com/ckfinder/userfiles/files/wawadib.pdfIn PDF document text
    • http://tdvvietnam.vn/webroot/img/files/gipedafap.pdfIn PDF document text
    • http://niengrangchuyensau.com/upload/contentFile/file/82364194984.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=2007+yamaha+rhino+450+service+manualPDF 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_off0000d1f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1F7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ea0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA0E 11084 bytes
SHA-256: ff73f8b42f7629a799883f20afa3551c44beb4d9b2971e63ab3732629db4867d
font_02_sfnt_off000103de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103DE 17092 bytes
SHA-256: 6a396a96f6a31684535ac6c1b43c77fe8f437789a195e5f6374c22e68f6576d5