Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8852a2e7588a34e…

MALICIOUS

PDF

103.2 KB Created: 2021-07-02 08:32:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 42aa4f99793f140f70dab305f5bc179d SHA-1: a8273878b0d32edc9b58e77a031a29778103b854 SHA-256: c8852a2e7588a34ea11076c5d26d542cdaca3b63872d6478f847cec065632857
96 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm for SEO poisoning or phishing. The ML classifier also flagged this PDF as malicious with high confidence. No scripts were extracted, and the document body was unreadable, but the heuristic firings strongly suggest malicious intent through URL manipulation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9874

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://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609b1a4941c83---90270749490.pdf
    • https://acryl-bg.com/userfiles/file/lurunusipekeliguzuj.pdf
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/inhi2r0i660d8unp0s5u0qdf2b/54895179570.pdf
    • http://beamstraffic.ae/amb/userfiles/file/lezifobomilafikumaxepidup.pdf
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ce94eeea5ad---55507603986.pdf
    • http://www.pilonidalsinus.gen.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606ef73d09b74---98932666503.pdf
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073e4dd2483a---mizosotor.pdf
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086c6eb864cc---65264316695.pdf
    • https://schmitz.cz/res/file/lazasafa.pdf
    • http://netinflux.net/userfiles/file/41176149721.pdf
    • http://colescastle.com/clients/875019/File/15200196391.pdf
    • http://auksozvynas.lt/userfiles/file/89074187417.pdf
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/6k34spmpki5t4a115m6hvhk0o0/9684142780.pdf
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/160982838551bb---71531891377.pdf
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160903227d7837---lujotenoxivowokaxureneji.pdf
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d4bfd203e3---296539715.pdf
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/g36ei9839cg8s0g6lju7g83eph/13432986778.pdf
    • http://yasairamenbar.com/uploads/files/nirofixafakujuvu.pdf
    • http://goref.ru/files/file/896274612.pdf
    • http://zawayakw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a69270ff8b---83594019433.pdf
    • http://dabaizhongxue.com/upload_fck/file/2021-6-13/20210613041658368229.pdf
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1608f3d272204b---19453588634.pdf
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb69de88a2d---84780058657.pdf
    • http://snotlicker.com/clients/10243/File/kolilepututi.pdf
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b56754d88d7---nanamezaxipadil.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=density+of+a+gas+is+found+to+be+5.46+g
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000115aa.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x115AA 16792 bytes
font_01_sfnt_off00012dc1.bin
f94eb37130ab4f3725ea881d720f62b147eca853f3f06646b8a241ddd56b3c1c
pdf-font-stream PDF embedded font (sfnt) at offset 0x12DC1 11184 bytes
font_02_sfnt_off00014801.bin
450eea5fc67953cc3bdc764260aa6f1739571c17331c9588074966c3dbef4c6c
pdf-font-stream PDF embedded font (sfnt) at offset 0x14801 16088 bytes
font_03_sfnt_off00015d32.bin
a75d3aa347b4c812666b683d98f4c6951ca687309481618a1b561b0ec84ebe10
pdf-font-stream PDF embedded font (sfnt) at offset 0x15D32 18760 bytes