Malicious PDF — malware analysis report

Static analysis result for SHA-256 281ce15aac947097…

MALICIOUS

PDF

84.0 KB Created: 2021-08-31 19:43:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 0a4aab2ec79f25104f912737d3c77783 SHA-1: d1e6996a1f7f477ec8d97ec18ef25e17fad35539 SHA-256: 281ce15aac947097b35f10fd234158efffe3dae6071eb337a756595012e3d3f0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links to other PDFs hosted on compromised WordPress sites, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. No scripts were extracted, and the document body was unreadable, but the heuristic firings clearly point to a multi-stage attack leveraging compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9011ca3af3---jipagipesimezasokelew.pdf In PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/160da7026691ae---27653369349.pdfIn PDF document text
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/quko2u6rmkdfp9bv7icbov57l6/61778162767.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1aced0bfe---29664371304.pdfIn PDF document text
    • https://bnbcostaverde.it/userfiles/file/18333400343.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/4qbac1pcc8ev5hv9npoaeghm9n/sisisufep.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a453f7c2c99---mimomagupelinij.pdfIn PDF document text
    • https://jaiminsales.com/ckfinder/userfiles/files/35424290395.pdfIn PDF document text
    • http://www.morenoroofing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097733731415---jugapu.pdfIn PDF document text
    • http://katachizu.com/img/news/files/favenagunuzuv.pdfIn PDF document text
    • https://soba05.org/wp-content/plugins/super-forms/uploads/php/files/56b1cf1001fcf1736971f48d4fab4d2a/dulukuxifovoguxemuvokuv.pdfIn PDF document text
    • https://xn--80aanugxqi.xn--p1ai/admin/ckfinder/userfiles/files/10159670425.pdfIn PDF document text
    • https://badoza.net/userfiles/file/57685195927.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608cb0c30a32c---juxarebasata.pdfIn PDF document text
    • http://florylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/taxavudibidoxorubedovu.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/202172784375474.pdfIn PDF document text
    • http://skogsformedling.se/bilder_umeny/File/punafil.pdfIn PDF document text
    • http://plnjl.com/userfiles/files/puvamewazupavepafuxuraf.pdfIn PDF document text
    • https://datawire.gr/files/files/fiwabusozolawokufoxok.pdfIn PDF document text
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/8e6df0c26643f75c598dfbe717da311a/zodasitiguniwitorifono.pdfIn PDF document text
    • http://poexali.org/static/image/_u/system/files/matisu.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/5630152703b3a40609e45d2c1ff7bff6/53728806923.pdfIn PDF document text
    • https://anjingliar2.com/contents//files/suganenamok.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=hoover+nextra+6+hnwl7146+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_off0000e04e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE04E 18668 bytes
SHA-256: 9d177a3db774f4531532ad87c1a621f104e84c9b93ffcad2e4157f211de919df
font_01_sfnt_off000110bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000128d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128D4 10808 bytes
SHA-256: cdf4386e52f4d266bda20a05455430c44ae1e5c94465d75310df2314c91b2b02