Malicious PDF — malware analysis report

Static analysis result for SHA-256 0a99860111e2b4f8…

MALICIOUS

PDF

76.8 KB Created: 2021-09-07 14:58:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: f1a1257bb48ff06dc68b11b078903c14 SHA-1: 5c9c62ded9717e902a9de157824dba709b95e5b2 SHA-256: 0a99860111e2b4f8485ef5b4b8e12e4eccf59e75de4f8704e9867a7adbc8075e
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to potentially malicious content. The ML classifier strongly indicated maliciousness, and the presence of multiple external URIs supports a pattern of redirecting users away from the initial document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://krisoc.ru/uplcv?utm_term=managing+oneself+ebook+pdf PDF link annotation
    • http://doks-films.com/pcms/content/file/52942047045.pdfIn PDF document text
    • http://vektorma.ru/uploads/assets/file/79416997749.pdfIn PDF document text
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/00c9d89ea303fbf9c8f7f6266150f7a3/59866691305.pdfIn PDF document text
    • http://avstralianature.ru/ckfinder/userfiles/files/vegazurijijekibedokorovu.pdfIn PDF document text
    • https://adrfarysz.pl/userfiles/file/pijapanubometupef.pdfIn PDF document text
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160d613871c4a0---wuxikutemopawinaxer.pdfIn PDF document text
    • https://bikeid.net/ckfinder/userfiles/files/mevev.pdfIn PDF document text
    • https://baxsporthorses.nl/userfiles/file/2613851718.pdfIn PDF document text
    • https://briljant-maleri.se/UserFiles/files/vulopuginidosesanuk.pdfIn PDF document text
    • https://hmjrgoldhockey.org/wp-content/plugins/super-forms/uploads/php/files/caef243a8d20c541a553167f4898599f/lavixibupefuvomuran.pdfIn PDF document text
    • http://ailizia.com/userfiles/wiguninezamiz.pdfIn PDF document text
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/e41ac189647a13c5c66ea6382f493ead/10560183532.pdfIn PDF document text
    • https://vipbeachhouse.com/uploads/editor/file/91783777978.pdfIn PDF document text
    • https://clearpatth.com/userfiles/file/97709434975.pdfIn PDF document text
    • https://paeonia.ch/userfiles/files/27032629474.pdfIn PDF document text
    • https://caffedisanto.it/file/69106938916.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608370cc9e076---49152087193.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/7e4c6ddc91b16ca1bfc3eace27c19f86/sifomajeka.pdfIn PDF document text
    • http://bmcsteel.com/uploads/baiviet/files/98427075540.pdfIn PDF document text
    • http://matchedtubes.de/userfiles/file/79867226649.pdfIn PDF document text
    • https://shrisaiexport.com/lightspeedweb1/file/70578780133.pdfIn PDF document text
    • http://rogersdesignhouse.com/uploads/files/47330446047.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608915c8e2195---fefowinim.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ce5416185d---92544951619.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_off0000bfa7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFA7 20888 bytes
SHA-256: 7a78e1e3946fb1be8285985ff3b8dd5e1be6fdefada8f415985d30c68eb7e2bf
font_01_sfnt_off0000f5e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5E1 10700 bytes
SHA-256: dbac08436dfdfa716e5335177b02171e62f00d402ca960453a97ccfb2bb88bd0
font_02_sfnt_off00010e1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E1B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1