Malicious PDF — malware analysis report

Static analysis result for SHA-256 2100cbf4d840a559…

MALICIOUS

PDF

119.1 KB Created: 2021-08-10 12:57:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f4c4ed69159138b65ded4652aaf65759 SHA-1: a12a9164427497b611b0ad5d62f347c8d5fc284d SHA-256: 2100cbf4d840a5595a17a93543746794699c9c44fc3bb612c41902e27108b3d4
116 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress installations or disposable domains. The ML classifier strongly indicates maliciousness, and the heuristic firings suggest this PDF acts as a link farm, likely intended to redirect users to malicious websites for phishing or malware delivery. No scripts were extracted, and the document body was unreadable, but the URL structure and heuristic data are sufficient for a high-confidence assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

Heuristics 6

  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://luminex.pl/upload/file/78308680067.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c3dfd20b20---80526786784.pdf
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/abfd392d1451f58646cbedcce1514d07/22165218372.pdf
    • https://investkwik.com/userfiles/file/jexesojolukivezuda.pdf
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609f6021ce94f---tajifufirotopu.pdf
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/160904c63a38ef---sivamimekabimaf.pdf
    • http://www.esthemed.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1609f3ad18412e---pofopitimefeku.pdf
    • http://agt.es/files/galeria2/files/20626936135.pdf
    • http://thedreams.cz/files/4579667814.pdf
    • http://buddhavehicle.com/userfiles/file/11699086167.pdf
    • http://79.170.40.182/boothtastic.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ffd48f4175---21674570564.pdf
    • http://kssi.ir/public/userfiles/file/jonikunokebipesozor.pdf
    • https://adikkeempat.com/contents//files/wanusetoronade.pdf
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b9ea44b498---ganifedut.pdf
    • http://rzn-house.ru/upload/file/83251192413.pdf
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0de69146ff---jorulemoxidovine.pdf
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609f3f53adb92---xifanifiwujunowaxado.pdf
    • http://haenuri.net/ckupload/files/5300541987.pdf
    • https://myparrotfood.com/user_files/files/zipusafotol.pdf
    • https://www.charroninc.com/wp-content/plugins/super-forms/uploads/php/files/e837f576c5d7fcdf8c799bd6c0f67b6f/fexegomenizojid.pdf
    • https://golf-tout-terrain.com/publish/page/file/vemewop.pdf
    • http://tlumacz-bialystok.pl/pliki/file/zusezudevabeziravasel.pdf
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/q2rle6u2pcrovuvh6pfll3bck5/52714548486.pdf
    • http://zamel2.pl/userfiles/file/44061644936.pdf
    • http://engineersclasses4competition.com/files/others/kiniduwefal.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=prayers+in+difficult+times
    • 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_off00017095.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x17095 16792 bytes
font_01_sfnt_off000188a7.bin
8f08639933299384d36f7f56e7ad3789df9c5a123344e5ed809b140f7b455bd8
pdf-font-stream PDF embedded font (sfnt) at offset 0x188A7 17292 bytes
font_02_sfnt_off0001b563.bin
71b3971cbb9b9efe1e410bb739b31b5d06ae9a711e9f0943588beb64cfb506f0
pdf-font-stream PDF embedded font (sfnt) at offset 0x1B563 10732 bytes