Malicious PDF — malware analysis report

Static analysis result for SHA-256 633cb60d9c564c4c…

MALICIOUS

PDF

101.2 KB Created: 2021-09-08 05:15:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 133510236c6a3e20c263f965a936e811 SHA-1: e602e4d1c9b756af92d1662434d2825ad6e97052 SHA-256: 633cb60d9c564c4c895568c0fc4b41ecbfa94d2184b37eb0d16d5fb6954b8631
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1190 Exploit Public-Facing Application

The PDF contains numerous links pointing to compromised WordPress sites, specifically targeting file upload functionalities within plugins like FormCraft and Super Forms. These links host other PDF files, suggesting a chain of redirection or a distribution mechanism for malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9938

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160878d7270448---zovamadebibowe.pdf
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/7497c7fe7f65334bb9a9eed68fe1bb5b/zukisilibodefodazegulegor.pdf
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/3704cc15de3793f37928e180f9dcb71f/wokijekilixafinugilu.pdf
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d25eb74694---16078440797.pdf
    • https://istanajp2.com/contents//files/tozirexupejiso.pdf
    • http://biurod9.pl/public/userfiles/file/70417123194.pdf
    • https://ikansambel.com/contents/files/jexotimowagovar.pdf
    • http://www.museopizarra.com/ckfinder/userfiles/files/87014098406.pdf
    • https://www.syria-report.com/sites/all/libraries/ckfinder/userfiles/files/297004458.pdf
    • http://architettoletiziamasciotta.eu/userfiles/files/7184428776.pdf
    • https://cavalier-hundezucht.ch/userfiles/file/71581096526.pdf
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7d14e9b9c---73521155457.pdf
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608b8cc2d82ae---gelegevijelabuje.pdf
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160948545722d9---zeritoz.pdf
    • http://eluvial.com/sites/all/sites/eluvial.com/files/99176399904.pdf
    • https://africanresearchcenter.com/userfiles/file/14610730921.pdf
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b4f9793ad9---bakatudifop.pdf
    • http://snnet.kr/board_pds/fckeditor/2021/08/file/99558980534.pdf
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/415e72f05b2e49b0729f959895991532/zeborile.pdf
    • http://a-swiss.com/upload/userfiles/file/61531961502.pdf
    • https://shindah.com/images/ckeditor_img/files/9766613345.pdf
    • http://www.mostex.sk/files/articles/file/kumib.pdf
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/16075dea4db1c1---dujajotixawidisesirid.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=advantages+of+complementary+feeding+pdf
    • 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_off0001246f.bin
4f6cd808817e18257d40e6258d9f7820a117e53ed5cb4e0dfbef8fc383ad7cc8
pdf-font-stream PDF embedded font (sfnt) at offset 0x1246F 19096 bytes
font_01_sfnt_off0001554e.bin
0aa19ae5d0f9cbe7468275e7354f06d761757ed1bf3e0aff974f72bc25a4a391
pdf-font-stream PDF embedded font (sfnt) at offset 0x1554E 11124 bytes
font_02_sfnt_off00016f24.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x16F24 16792 bytes