Malicious PDF — malware analysis report

Static analysis result for SHA-256 efa5b362dd760b27…

MALICIOUS

PDF

72.5 KB Created: 2021-09-30 17:05:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 2bf09c7f14547144bc62c4c68c40523b SHA-1: 06174145366f191f66c8326f927107df7ad2d4e9 SHA-256: efa5b362dd760b275f41f5950880dcfd14a5027c31e9636e9f67a27975d9f087
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites and disposable hosting. The ML classifier strongly indicates maliciousness, and the heuristic firings confirm the presence of a link farm designed to redirect users. The primary purpose appears to be directing users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 5

  • 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://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/d4b12a58795f7089531a5eb23564cf53/10322096578.pdf In PDF document text
    • https://kidneystonetreatment.in/userfiles/files/39396692982.pdfIn PDF document text
    • https://mayphoviet.com/media/ftp/file/20849175843.pdfIn PDF document text
    • http://www.f2dassociates.com/userfiles/file/nipijevulaluxofodefavomi.pdfIn PDF document text
    • http://atthaya.com/file_media/file_image/file/77964683168.pdfIn PDF document text
    • http://ulv-fogger.ru/d/files/reteso.pdfIn PDF document text
    • http://kondicionery-domodedovo.ru/upload_picture/file/12260905194.pdfIn PDF document text
    • https://gulfsupremesa.com/ckfinder/userfiles/files/17228775683.pdfIn PDF document text
    • http://receptlap.hu/files/68902227278.pdfIn PDF document text
    • http://grafittipng.com/userfiles/files/pokamejuzosizonepaxeru.pdfIn PDF document text
    • https://gikguamerica.com/userfiles/file/90585962856.pdfIn PDF document text
    • https://bonaparte.cappencms.com/templates/files/92671475021.pdfIn PDF document text
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614af039b1678---walogexalugogas.pdfIn PDF document text
    • http://ortosprendimai.lt/userfiles/file/31604838149.pdfIn PDF document text
    • https://www.privathospitaletkollund.com/ckfinder/userfiles/files/96945850958.pdfIn PDF document text
    • http://cobe-ing.it/userfiles/files/meladitulanowoxuzumidutax.pdfIn PDF document text
    • http://elsped.hu/files/file/furalelarovomuvunim.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/denog.pdfIn PDF document text
    • https://lengthening-sldf.com/userfiles/file/felusuvisewawibi.pdfIn PDF document text
    • http://alarmy-kamery24.pl/userfiles/file/90615434410.pdfIn PDF document text
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/3mc6dp2i50a7h7lh2fm3se6uvj/49568025874.pdfIn PDF document text
    • http://js-space.de/userfiles/file/68371575786.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=power+vpn+mod+apk+revdlPDF 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_off0000b315.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB315 18572 bytes
SHA-256: 85f57a9a1b6c1637d61e20f8a2a478f61475e939896461af09b59da88dfc8de5
font_01_sfnt_off0000e32c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE32C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fb43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB43 10440 bytes
SHA-256: b2df5cf386c56bf176621342fd5cc555faabbee333ea9593dfbc1cf3280c7088