Malicious PDF — malware analysis report

Static analysis result for SHA-256 0fa50e3b0c735870…

MALICIOUS

PDF

79.3 KB Created: 2021-09-08 07:28:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: af55136de1fa84873b79a0d1656faf28 SHA-1: 65a179ba28d3d65eab9b03410e179a636ef2c87c SHA-256: 0fa50e3b0c735870521b6170184b342fe50e81f235f7fabf2463fec41e0805eb
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites hosting other PDF files. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest this PDF is part of a link farm designed to redirect users to potentially harmful content. No scripts were extracted, but the structure and URL distribution are indicative of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 http://x-site.by/upload/editor/files/15555932885.pdf In PDF document text
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/5e7c51d0f90ee1d74d978d46e45d8e5d/porabukuvigokulofefebu.pdfIn PDF document text
    • https://nowackleverkusen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607af5a02801d---dijogasup.pdfIn PDF document text
    • https://lostsoulsmemorialnj.org/wp-content/plugins/super-forms/uploads/php/files/d084ff3c5070716bbfc45f6e197f11ff/fajawovag.pdfIn PDF document text
    • https://adtw1.com/ckfinder/userfiles/files/gobovexuguw.pdfIn PDF document text
    • http://maschimaurizio.it/userfiles/files/fajiduzub.pdfIn PDF document text
    • http://padgettlawreunion.com/clients/79772/File/lobolupevojiwobu.pdfIn PDF document text
    • http://canphantich.net/Images_upload/files/97936337702.pdfIn PDF document text
    • https://micsys.in/userfiles/file/86925553864.pdfIn PDF document text
    • http://video-cycling.de/files/file/68871238775.pdfIn PDF document text
    • http://tourbusan.net/FileData/ckfinder/files/20210701_01A269F2750BA87C.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/05ed1d34faf8992a07a3b9134e119162/79540375504.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7322242712---59523861448.pdfIn PDF document text
    • https://cursosadistanciayonline.com/medios/files/tozajukibotukijexabovig.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136aec6be283---30592623977.pdfIn PDF document text
    • http://interno-kazan.ru/upload/files/12448546580.pdfIn PDF document text
    • http://ithalattagarantibelgesi.com/resimlerfiles/66789726854.pdfIn PDF document text
    • http://studioassociatoemc.com/userfiles/files/dagivu.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/f9109647a614b076d4b48e8924b2ddb0/puxavupaj.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1612815e6ac171---68347932710.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=superficial+vein+thrombosis+pdfPDF 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_off0000d245.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD245 16904 bytes
SHA-256: 5e64ce37d6bcfe01f30006bb5a2001b5bd665ace2b66b165db4a3e68448555b2
font_01_sfnt_off0000fda9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDA9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000115c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115C0 11264 bytes
SHA-256: 718f2fd63cdac36c826060c52a995b1707785578bf46b031ad826a10fbdf4b05