Malicious PDF — malware analysis report

Static analysis result for SHA-256 0177c8eeb4d903f4…

MALICIOUS

PDF

80.7 KB Created: 2021-09-17 10:53:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 8fe3a33a2f4d34254c907a99796d1d19 SHA-1: 8b01ab3b59523ab59563ad19eb6c30be99296d1d SHA-256: 0177c8eeb4d903f4006b4d7551be4a49773aeba324aeb4801b99c879cfd75d50
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 are hosted on compromised WordPress sites or disposable domains, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the presence of multiple 'link farm' heuristics further supports its malicious intent. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://ketchas.ru/uplcv?utm_term=inshot+free+version PDF link annotation
    • http://myredm.ru/uploads/file/nakexedewesavunupobu.pdfIn PDF document text
    • http://karimeh.com/public/userfiles/file/sepijarelo.pdfIn PDF document text
    • https://irantruck.ir/data/file/66956040518.pdfIn PDF document text
    • http://aasghsflqsae.handylover.com/upload/files/godejinesosilugafopav.pdfIn PDF document text
    • https://astdubai.co/userfiles/files/xepufofixosene.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/16133889724596---zexajimukatuzarevurur.pdfIn PDF document text
    • http://yushendesign.com/images_fck/file/1631103958.pdfIn PDF document text
    • http://ewtch.com/upload/files/kimejegadepamiponubog.pdfIn PDF document text
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/3f2b01c2cb631c6abdcd7f8d458e86ea/3052361570.pdfIn PDF document text
    • http://naturalmis.com/userfiles/file/14421687105.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141fdaf4def2---53172179111.pdfIn PDF document text
    • http://waterlootour.com/FileData/ckfinder/files/20210911_34EC5ABC0CB23081.pdfIn PDF document text
    • http://hortherbpublisher.com/files/upfiles/file/zagakikexosi.pdfIn PDF document text
    • https://gretajensen.com/ckfinder/userfiles/files/bowugutalitapafije.pdfIn PDF document text
    • http://rococosofa.com/files/files/mudukam.pdfIn PDF document text
    • http://thunderstar.cn/userfiles/file/20210914143326805051373.pdfIn PDF document text
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/iorc9u938kjb2jnm97s30bh6sg/vanerovop.pdfIn PDF document text
    • http://baominhlabors.com/upload/files/bejodejatutex.pdfIn PDF document text
    • https://seerupit.dk/assens/file/noliv.pdfIn PDF document text
    • http://dribblebar.pl/userfiles/file/zubenagitob.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142e5af295ee---texumix.pdfIn PDF document text
    • https://oxfordjsr.com/userfiles/file/30347745461.pdfIn PDF document text
    • http://thietbikhachsanvinhhung1.com/upload/files/76929160136.pdfIn PDF document text
    • http://tieulongcopro.com/luutru/files/82742676747.pdfIn PDF document text
    • https://mamalight.net/business_school/uploads/file/16708260415.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_off0000d99a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD99A 17756 bytes
SHA-256: 1e523f3930ef5ceb293466df3a8af6d962a8f2108fab697b80762f0f01e8aac3
font_01_sfnt_off0001070b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1070B 10120 bytes
SHA-256: e28f2eb43db7f381d4807ed5b30336eaa69b1d8691ee600bff1ca69a467c2d79
font_02_sfnt_off00011d99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D99 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1