Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a9f696572441ee6…

MALICIOUS

PDF

69.0 KB Created: 2021-09-24 19:46:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 5d0915ab5b514f4b07180c0143d0e4bb SHA-1: 7628e8b6fe1a52f79d0d80eeb20df14190995228 SHA-256: 3a9f696572441ee67b18a8b37f610043b9d0fe62374a2b3895cc7e131c9c4a44
116 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to compromised WordPress sites and disposable domains, suggesting a link farm designed to redirect users to malicious content. The ML classifier strongly indicates maliciousness, and the malformed stream length heuristic further supports exploit activity. No scripts were extracted, but the overall structure and URL distribution point to a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 6

  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://drafthe.ru/uplcv?utm_term=stickman+warriors+apk PDF link annotation
    • https://babycloud.ro/app/webroot/files/userfiles/files/wibevabijomotexusiro.pdfIn PDF document text
    • http://spain-ex.com/images/blog/file/sezixonuwer.pdfIn PDF document text
    • http://adhunikjewellers.com/ckfinder/userfiles/files/jekumo.pdfIn PDF document text
    • http://melly-incendie.fr/img_db/zikunavuvawavisu.pdfIn PDF document text
    • https://tidurmalam.com/contents/files/27704988185.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16133b4b363df6---poxoxenipuxed.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145469f49763---jegorevofif.pdfIn PDF document text
    • http://jingkangchem.com/upload/files/vowete.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/161328cb0c1812---mejus.pdfIn PDF document text
    • http://iccjsc.vn/images/uploads/files/jodafuduxewedav.pdfIn PDF document text
    • http://elfuklid.cz/foto/Image/file/39251121260.pdfIn PDF document text
    • http://zeminyerkaplama.com/upload/ckfinder/files/wupileworudulibiru.pdfIn PDF document text
    • http://takramaipai.com/mypicture/file/4282738274.pdfIn PDF document text
    • https://kebecelectrique.com/upload/editor/file/gobimavuxuzosuliroj.pdfIn PDF document text
    • http://szjg.hu/images/file/wegugoxokofinigajobi.pdfIn PDF document text
    • https://baxsporthorses.com/userfiles/file/83551119246.pdfIn PDF document text
    • http://hitmet.slektenkaas.com/bilder/file/57460927005.pdfIn PDF document text
    • http://instant-image.net/UserFiles/Site/File/73423746861.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/161443d71cd2c4---zitizilerufegag.pdfIn PDF document text
    • https://shiprapublication.com/uniformkontakt/userfiles/image/files/fomupofegifi.pdfIn PDF document text
    • http://balaton.varosom.hu/userfiles/files/jedafotewoxerujopafu.pdfIn PDF document text
    • https://dialogueinpraxis.net/files/docs/34994188004.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_off0000adb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xADB0 10608 bytes
SHA-256: ee405a757d8855586de28da059840322a7731a3ebc5a2b1e42e0e03751e12a21
font_01_sfnt_off0000c5fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5FA 16064 bytes
SHA-256: 245b2c02f8062cdc3882e646613e9bab4aebf6a3e2a51ebe019100fd7e7163b2
font_02_sfnt_off0000eee0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEE0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1