Malicious PDF — malware analysis report

Static analysis result for SHA-256 e1efa79169ca76ac…

MALICIOUS

PDF

73.0 KB Created: 2021-09-02 13:28:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 38842d4bf698b9ba04c9c1ba0a56857c SHA-1: 96f1898d799b6dd294550a6fb0bee1fae846da18 SHA-256: e1efa79169ca76acb80047f8a4baa2b00a4991b8bd4fea8bc9495b406bc71263
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 or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the heuristic firings suggest it's part of a link farm strategy. While no scripts were extracted, the structure and embedded links are indicative of a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://synthecinter.com/userfiles/files/83566887155.pdf In PDF document text
    • http://creativetechno.in/userfiles/file/xudefudixufaxa.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16093acb079e8b---21939973769.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/58fbece09b82ee7696a60dc9954e5885/xizavevot.pdfIn PDF document text
    • http://vrieshorst.nl/images/uploads/file/90323949512.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609820638407c---naximegozuribavoditug.pdfIn PDF document text
    • https://livre-d-art.com/ckfinder/userfiles/files/retuw.pdfIn PDF document text
    • http://ardechetendancebrut.fr/userfiles/ardechetendancebrut.fr/file/87368748716.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610843d27edc0---pidikenibowuni.pdfIn PDF document text
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1609475aa99d08---toxozusonesumojebegusota.pdfIn PDF document text
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/7d412q0ma3nlu8k7ietddimcuc/22354717129.pdfIn PDF document text
    • http://ssatripoli.org/userfiles/file/31157562841.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ec9ebc1a1aa---2772131429.pdfIn PDF document text
    • https://md-bud.pl/szklo/photos/file/76667708960.pdfIn PDF document text
    • https://hglobaltourb2c.com/FileData/ckfinder/files/20210728_0185B249D645DB6B.pdfIn PDF document text
    • https://geneolock.com/locktactyuma/userfiles/file/29912399840.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb1b4fe18dd---busegivunuzad.pdfIn PDF document text
    • http://tunglamgarden.com/images/fck/file/7903923640.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/160a698e59ca1b---50573843632.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=open+file+dialog+c%23+filter+pdfPDF link annotation
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/080a0add2161c1fdd916d55bfaaa897e/83728869591.pdfIn PDF document text
    • 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_off0000bb17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB17 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d329.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD329 16716 bytes
SHA-256: 6cee5d48bb29005bf7b61dfa4a22659b21535e9517b4bae3b654cc25473e4def
font_02_sfnt_off0000ff34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF34 10456 bytes
SHA-256: cc622003dd51bb46e7665ea09e16bcd8fe319c9025a356fcbe9d058702d853bf