Malicious PDF — malware analysis report

Static analysis result for SHA-256 88d6625ab3491953…

MALICIOUS

PDF

71.6 KB Created: 2021-09-24 18:52:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6db3dc77d9ebdcf15af85d5cf4f603b6 SHA-1: 0dcdcca94d6f469d923bf1c084a0e8d4788b981d SHA-256: 88d6625ab349195300ae2cb7b00ad296ec1c85ef6505f277171274008215c560
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple domains, some of which appear to be compromised WordPress sites. The ML classifier strongly indicated maliciousness, and the presence of numerous links suggests an attempt to trick users into downloading a file. No scripts were extracted, limiting the analysis of specific execution behaviors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://nifaelectronics.com/userfiles/file/28975113099.pdf
    • https://htmlpanda.rockeit.com/userfiles/file/dokenepatesikevotob.pdf
    • https://dovolena-jiznicechy.cz/uploads/durenu.pdf
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143962d7b8ba---dunubojozizibivuzoturi.pdf
    • http://neodev.space/wp-content/plugins/formcraft/file-upload/server/content/files/1613464340330a---gesosoranuwawijudi.pdf
    • https://fiscconsulting.com/userfiles/file/41970602260.pdf
    • https://seltec.io/images/uploads/files/39617160874.pdf
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/bb33751e07eb9ef8b67b1cd19041b0c5/nugotozikevunatomit.pdf
    • https://fundacjanadzieja.com/images/wyswig_images/file/52677409845.pdf
    • https://paroles-vives.com/ckfinder/userfiles/files/jumikaxerufavokatebo.pdf
    • http://hflchw.com/upload/file/womavemesimajekawok.pdf
    • http://www.og2c.com/images/file/1743021169.pdf
    • http://globalcenterhotels.com/bot/ckfinder/uf/files/6758310091.pdf
    • http://schodylux.pl/userfiles/file/98762436.pdf
    • http://stroyindustry.com/userfiles/file/25775268564.pdf
    • http://holmeslawfirm-iowa.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/koponodowo.pdf
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614723dec5f41---pekumenew.pdf
    • http://www.corazondelsol.es/ckfinder/userfiles/files/6467183772.pdf
    • http://ciaooo.ru/uploades/userfiles/file/zitabedizanuxelijaluv.pdf
    • https://rumahbaruku.com/contents/files/pesifuvej.pdf
    • http://gniortho.com/files/Upload/file/50867395420.pdf
    • http://leeclinic.kr/userData/board/file/vufufuwotujatenot.pdf
    • http://sabaispa.net/userfiles/file/reradetisepasewuzesin.pdf
    • http://canphantich.net/Images_upload/files/53225424490.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=key+download+manager
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b494.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB494 16792 bytes
font_01_sfnt_off0000ccab.bin
9ecfa68b05047aafad66ec1424cec84350d798c56496e34a410fd150ffd4ecc8
pdf-font-stream PDF embedded font (sfnt) at offset 0xCCAB 10424 bytes
font_02_sfnt_off0000e418.bin
d990e5730e9ac79d9f9bc3a4c7898a020652c073f4726520a5a2ec29fd85898c
pdf-font-stream PDF embedded font (sfnt) at offset 0xE418 17316 bytes