Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1859af06b6f1a77…

MALICIOUS

PDF

76.1 KB Created: 2021-09-20 10:25:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 7ee2e3db35434d4561c6a3ba5320c84b SHA-1: 5ce9c37f78862ed50e8775cb49d3e73532c56e07 SHA-256: b1859af06b6f1a77dabee14c908728303a06e26d5eb6cfdfae2c40c8d3f6975e
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing or trojan. It contains numerous URLs that form a link farm, many hosted on compromised WordPress sites, suggesting an attempt to redirect users to malicious content. The document body is heavily obfuscated, preventing analysis of its specific content, but the overall structure and heuristic firings indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://huntic.ru/uplcv?utm_term=secure+contacts+android PDF link annotation
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1612f10b5bfa70---79197046225.pdfIn PDF document text
    • https://aukshanya.promosing.com/alpha/ckfinder/userfiles/files/fesezimapadutekifodid.pdfIn PDF document text
    • http://truhlarstvi-strakonice.cz/files/file/ralepelemifafegok.pdfIn PDF document text
    • http://pedraferro.com/files/files/67239898450.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cd4a6b2770---defawevu.pdfIn PDF document text
    • http://www.pacautomarketing.com/file/rudagisorazudakabidi.pdfIn PDF document text
    • http://cssh.es/img/file/10395132928.pdfIn PDF document text
    • http://www.tempshift.com/app/webroot/files/uploadimagesfile/6703708160.pdfIn PDF document text
    • http://bonezi.morefriendship.com/upload/files/lanixarurimorituvan.pdfIn PDF document text
    • http://boardmark.com/files/file/5889977887.pdfIn PDF document text
    • http://caudafotografia.com/userfiles/files/tiwusoboxebovojewa.pdfIn PDF document text
    • http://pazarziraat.com/userfiles/file/nitidelexa.pdfIn PDF document text
    • https://marwaservicecenter.com/nbloom/fckuploads/file/mofijobufasux.pdfIn PDF document text
    • http://shamayachts.com/upload/file/24253680675.pdfIn PDF document text
    • http://sintellect.ru/Repository/file/45469540007.pdfIn PDF document text
    • https://oncetrabzon.com/resimler/files/23605505521.pdfIn PDF document text
    • https://aydin-elektrik.com/resimler/files/93213649003.pdfIn PDF document text
    • http://khautrangkhangviet.com/upload/img/files/46873926637.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e79aa5bbd8---fexozaxuledomomomaxur.pdfIn PDF document text
    • https://mysmartedu.com/uploadimages/files/juzopemofebunirutudegeguz.pdfIn PDF document text
    • https://dascalita.ro/app/webroot/files/userfiles/files/jeranosalapedamari.pdfIn PDF document text
    • http://littlepearlbooks.in/data/eimages/file/linejes.pdfIn PDF document text
    • http://tce.vn/imagesflashupload/file/8597435374.pdfIn PDF document text
    • https://coloreverything.love/wp-content/plugins/super-forms/uploads/php/files/a4289c7250be59f37595706e78b0ea48/zikokemibivutavifagezufe.pdfIn PDF document text
    • 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_off0000c721.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC721 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000df33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF33 16844 bytes
SHA-256: 1f84cbcdd1dd597876abb3b8d71ea531521c6d8b47fbafa054b450868e3c0e0d
font_02_sfnt_off00010a8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A8F 10492 bytes
SHA-256: db7d7b1d5eb0b5b812ce29c8fbbac57e85ae9d0d7886ceb8d44e32404e38fde5