Malicious PDF — malware analysis report

Static analysis result for SHA-256 b251f45c9d4c3b6b…

MALICIOUS

PDF

88.5 KB Created: 2021-08-03 12:41:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: bdad40cd94a71570143fe4160d804c0c SHA-1: b480d588e4abf5b59b0a3739611e843f84b59111 SHA-256: b251f45c9d4c3b6b8980158afb6f0db10126e7b30f8c1fcbb61ee4d8689e8c55
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to compromised WordPress upload directories, suggesting an attempt to host or distribute malicious files. The ClamAV detection and ML classifier further support its malicious nature, likely as a phishing or trojan delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/d659509e9ccbc5e906d4a00ae4215224/labegesoxemigelakudawud.pdf In PDF document text
    • https://martybermanassociates.com/wp-content/plugins/super-forms/uploads/php/files/2ce6df79df84bc66d00111e27084e7b9/57325707706.pdfIn PDF document text
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/a9648b66bd45742fbc22c81f803e0a3b/63942934872.pdfIn PDF document text
    • https://nilsahost.com/calisma2/files/uploads/50212150959.pdfIn PDF document text
    • http://greenlivinggarden.com/htdocs/UserFiles/file/38412612318.pdfIn PDF document text
    • http://autoshiftbid.com/fckeditor/userfiles/file/4082355552.pdfIn PDF document text
    • http://www.justgiveahand.org/wp-content/plugins/formcraft/file-upload/server/content/files/160969e96ee9aa---gisajoguvibomirogumufene.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/e31836b98114400d390788fbe91ab9e2/fupututalakafagal.pdfIn PDF document text
    • https://gearforfree.com/wp-content/plugins/super-forms/uploads/php/files/do1i8u91d7vdkubp8pkdp43mru/43360673846.pdfIn PDF document text
    • https://stillwaiting.org/userfiles/file/fupolunuzidixataxom.pdfIn PDF document text
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086e6f827b97---88749234433.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/8pkmsjon9vdmpemklmj6kr8ggc/23335831851.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/e2fa41c2642be5a367162f4112831874/xuzulajuwagatomiwa.pdfIn PDF document text
    • https://chatsystem.site/js/ckfinder/userfiles/files/63492933377.pdfIn PDF document text
    • http://czdashan.cn/uploadfile/file/2021050707165573499.pdfIn PDF document text
    • https://pestresolution.pt/site/upload/file/87480079340.pdfIn PDF document text
    • http://myphamlulanjina.com/upload/files/kosafizid.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/160b2e5f5d8654---26252965433.pdfIn PDF document text
    • http://www.haztartasigepszakuzlet.hu/pics/file/nujodigobirugedije.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609493772e930---sonakumokitofesoxuk.pdfIn PDF document text
    • https://myphi.biz/nbloom/fckuploads/file/10807539630.pdfIn PDF document text
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/b53900d5addf89ca20b1aea338204494/24533454452.pdfIn PDF document text
    • https://invest.pl/userfiles/file/84070470773.pdfIn PDF document text
    • http://webinside.pl/userfiles/file/18725018301.pdfIn PDF document text
    • https://greyquotient.com/wp-content/plugins/super-forms/uploads/php/files/7dd7eea6622a9ca08ce5d73d1c94c98e/fuwikegavule.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=how+to+take+apart+a+washing+machine+for+scrapPDF 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_off0000f5b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5B6 16712 bytes
SHA-256: 7a953651a3836cde53294bc3c14541e73628da89621e98a7781912436de242f9
font_01_sfnt_off00012110.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12110 11048 bytes
SHA-256: 833a069e63407f251911e0c5d59f07793b1980c448ff335e1b892a7d261bb551
font_02_sfnt_off00013aaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AAF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1