Malicious PDF — malware analysis report

Static analysis result for SHA-256 dafdcf54e271fc97…

MALICIOUS

PDF

98.6 KB Created: 2021-07-16 12:24:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 43b23f80b42e240b2a92e13a6ed3bde6 SHA-1: 1ec895450239980669d92db1ab8c3e9a9b16cec0 SHA-256: dafdcf54e271fc9772dcedc06b849663891eb5e8fc8b69d80c08ca5c6fc16c1b
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 CMS upload directories or are hosted on domains suggestive of disposable hosting. The ML classifier strongly flagged this PDF as malicious, and the heuristic firings indicate it functions as a link farm. No scripts were extracted, but the primary function appears to be directing users to potentially malicious external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://rockoncharters.net/home/rock/public_html/ckfinder/userfiles/files/delilufulax.pdf In PDF document text
    • http://ashioke.com/images/library/File/jegomirolaw.pdfIn PDF document text
    • http://trevelci.ru/ckfinder/userfiles/files/pujesalojukavonefiva.pdfIn PDF document text
    • http://phongkhamthienhoa.vn/images/files/gobadef.pdfIn PDF document text
    • https://red-adlay.com/upload/files/77489506594.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d8d10173189---rijezanoleruwetisubelute.pdfIn PDF document text
    • http://yuhenganquan.com/userfiles/file/20210603101212_1796111362.pdfIn PDF document text
    • https://myupfield.link/wp-content/plugins/super-forms/uploads/php/files/tk9e52t597gv23lbhe24od79b4/kaxifatigu.pdfIn PDF document text
    • https://igescanada.com/ckfinder/userfiles/files/gixopofalobapagetusiw.pdfIn PDF document text
    • https://perfecthospitals.org/FCKeditor/file/32494341019.pdfIn PDF document text
    • https://technok.cz/wp-content/plugins/super-forms/uploads/php/files/75b053c35378c5db94ff5375f48a4233/barovikikewosole.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac247aba8a4---matafatemulu.pdfIn PDF document text
    • https://menu2uplus.com/images/file/5997728034.pdfIn PDF document text
    • https://semagro-msw.ru/pics/images/file/gamovo.pdfIn PDF document text
    • https://ambalatender.com/upload/files/30318980215.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-7-4/20210704121006785164.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091e3b59caec---3995277592.pdfIn PDF document text
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/de6b9ac48f6da2be05764bad21e2f6f1/vutiwexajepunumijo.pdfIn PDF document text
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/2gk5tj330golo4g8mcfqimibf2/66005342942.pdfIn PDF document text
    • http://gphs84.com/clients/866382/File/32450352427.pdfIn PDF document text
    • https://universitecentrale.net/uploads/FCK_files/file/13025832021.pdfIn PDF document text
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/h7ocoa8iu4tv230vumkl3tmspo/begexedozexusivodutudu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=square+root+of+756PDF 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_off00011eee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EEE 17852 bytes
SHA-256: 4dec9d5acb6d98a6ea71fef5fc360e542395b8ea6b81dba84c9e0d877908cddd
font_01_sfnt_off00014d68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D68 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001657f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1657F 10472 bytes
SHA-256: 48084c9bd9cfc97fdc698e39a48d9c8bf062aee72e84d7afa296579502f1883e