Malicious PDF — malware analysis report

Static analysis result for SHA-256 c160d4028630eae4…

MALICIOUS

PDF

83.1 KB Created: 2021-09-18 19:31:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1d6fd5a1a256ab39a4bfd30b851401d1 SHA-1: 4b29daed4a448806954f97a8cd68c8e219ab6091 SHA-256: c160d4028630eae4da3eeea300e6c357e3ce23eaae46fbc2af19746f89cad3ab
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites and are structured as a link farm. The ML classifier strongly indicates maliciousness, and the heuristics suggest the PDF is designed to redirect users to potentially harmful content hosted on these compromised domains. No scripts were extracted, but the primary attack pattern appears to be social engineering via a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/16136ead345146---jurajikatozupegofavo.pdf
    • http://pcwenhua.com/uploadimg/file/1631697392266783214.pdf
    • http://cdmatik.com/uploads/file/74373188988.pdf
    • https://olgunbey.com/upload/ckfinder/files/34381273840.pdf
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613feaccbef52---sudabogupiwo.pdf
    • https://tadimtursu.com/image/files/fugefevuzukabomirudufuxum.pdf
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613db0964357b---48930323662.pdf
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136339635473---82957969326.pdf
    • https://kientrucqhouse.com/uploads/image/files/rafek.pdf
    • http://www.marcelasemper.com/wp-content/plugins/formcraft/file-upload/server/content/files/161380a4f5d65d---peletopimok.pdf
    • http://topenglish.sk/app/webroot/gallery/files/tifopizosoki.pdf
    • http://grappin-annat-como.com/userfiles/grappin-annat-como.com/file/biviwagoladobatadofavopo.pdf
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/161377196762b4---fanesizuxopinaluwavog.pdf
    • http://polymer-optix.de/userfiles/file/54867516632.pdf
    • https://hoangmailogistics.com/asset/site/files/45259497127.pdf
    • http://sinocelltech.com/filespath/files/20210912152728.pdf
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135b28391430---10033468179.pdf
    • https://toolsatool.com/userfiles/files/sinozosevasivi.pdf
    • http://orthopaede4you.de/userfiles/file/womuverajuxowisobame.pdf
    • https://carolinevlieghe.fr/images/file/76824026676.pdf
    • https://agrando.cz/files/file/82770902680.pdf
    • https://pima-alarms.rs/slicice/file/78526642210.pdf
    • http://cameranichietsu.com/luutru/files/xikovaxi.pdf
    • https://franchise-vietnam.com/app/webroot/img/files/tajesuduni.pdf
    • http://taiwanquinoafamily.com/shopadmin/upload/files/33437388420.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=snyder+version+of+justice+league
    • 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_off0000de8d.bin
1211e815b7e393f5255568ad7c3b79e30c4f34e87ea2d17789d9d485e6f47198
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE8D 17580 bytes
font_01_sfnt_off00010c52.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C52 16792 bytes
font_02_sfnt_off00012469.bin
c282173acd73005f0e32f63ca2892a53edfd3fde49384c0a5f035feba41af8eb
pdf-font-stream PDF embedded font (sfnt) at offset 0x12469 11136 bytes