Malicious PDF — malware analysis report

Static analysis result for SHA-256 b966516b707e4e9c…

MALICIOUS

PDF

75.9 KB Created: 2021-09-12 21:03:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: c9f54b95b5409e7ac05a98ea12075293 SHA-1: d8d2653079cdedc68184764f25562aab177635ea SHA-256: b966516b707e4e9c911db24ee8cf82059cd5c48e58bac4715624b4ca195d1a0c
96 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs, many pointing to compromised CMS uploads or disposable hosting, as indicated by the 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristics. The ML classifier also flagged this PDF as malicious with high confidence. The document body is heavily obfuscated and unreadable, suggesting it's not intended for human consumption but rather to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://ibrahimkoc.com/images/Media/files/guwibizazozexujunalu.pdf In PDF document text
    • http://goodtraefarm.com/ckupload/files/48324015216.pdfIn PDF document text
    • http://webspace.mysdam.net/images/newsletter/files/kejew.pdfIn PDF document text
    • https://tenshinorchids.com/FCKeditor_upload/file/kizukubomik.pdfIn PDF document text
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/5f1c15a99c9cd243f2d543596915e4a9/wubowipuluxosasejapizul.pdfIn PDF document text
    • http://eamenfaraz.com/cache/fck_files/file/vazavekafasobi.pdfIn PDF document text
    • http://caythuocnam.org/images/files/luriwizasalel.pdfIn PDF document text
    • http://855solution.com/htdocs/cljr/data/files/50389260424.pdfIn PDF document text
    • http://sovaimm.it/userfiles/files/90737740232.pdfIn PDF document text
    • http://skolky.info/foto/images/file/40363043830.pdfIn PDF document text
    • https://alrukn.co/userfiles/files/41350629002.pdfIn PDF document text
    • http://haokunchem.cn/upload/files/tifobisabu.pdfIn PDF document text
    • http://al-bandak.com/userfiles/file/53226851769.pdfIn PDF document text
    • https://autosaloncenter.com/uploads/file/geposijajetotujizisu.pdfIn PDF document text
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/1613a79bd5eaa7---nitasab.pdfIn PDF document text
    • http://iscelenie.info/files/file/fuxabizaxifajefozekofifom.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/0d00b5252d2067dc59b3a8fafb156fc6/paxegepedikotezaguxoxaf.pdfIn PDF document text
    • http://abc-tel.ru/data/File/metakiridubisupuvi.pdfIn PDF document text
    • http://swancentive.com/cote_dor_import/admin/ckfinder/userfiles/files/lifujugagugivek.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/4f407bee85506f94d348d95a3883fdf1/moxibezapagolepiwawuved.pdfIn PDF document text
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/16138f418ed63d---91641481196.pdfIn PDF document text
    • http://atomiccm.com/userfiles/files/11085520554.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=best+android+vector+drawing+appPDF link annotation
    • http://s292376414.onlinehome.fr/datas/imgmail/file/84887449931.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_off0000c251.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC251 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000da63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA63 17408 bytes
SHA-256: ade8402be09a988360d55ffa1c3f32db80eb3e436ab75435a9412ba73cb76d25
font_02_sfnt_off0001074f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1074F 10848 bytes
SHA-256: 509ea0a93af1d1637b8718293e362b972fa38c3eb5c4f4d34e2fb5303399dba0