Malicious PDF — malware analysis report

Static analysis result for SHA-256 88672ba74903c3bf…

MALICIOUS

PDF

83.0 KB Created: 2021-07-03 06:27:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3372fcdfa5c6c11b0a346e773280ec68 SHA-1: 181d2182fe700b0a14af3a6cc5d120fc0c798370 SHA-256: 88672ba74903c3bfa969d9bd6f8c97b81acfe748016d8dbada104e4557333648
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and other disposable hosting. These links likely serve to redirect users to phishing pages or download further malicious payloads, aligning with the 'Spearphishing Attachment' technique. No scripts were extracted, but the nature of the embedded URLs suggests a watering hole or redirection attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://irlanc.ru/uplcv?utm_term=curl+use+proxy
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160bbd5b5c5318---66669425177.pdf
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/736af99b1bc784b77aae7ce30544c185/77640389225.pdf
    • http://pomocnaukowa.net/Upload/file/xoligodosadazadegufefopuv.pdf
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16088e5e630901---79205710891.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608658c306177---3068660280.pdf
    • http://sacoorhealth.pt/site/upload/file/bojuribexevufumikix.pdf
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/160ae2a9c1a95e---vipopagoweg.pdf
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/ed462a46b926fb3e458da7344bfe4814/97627092483.pdf
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160944a8d7e3f7---94861696916.pdf
    • https://xn--80aaa1arbfjoe3bzh.xn--p1ai/data/files/57375828011.pdf
    • https://repare-ton-smartphone.com/userfiles/file/89195168969.pdf
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/0a9c82ccb68c3a588892716c6289a7aa/kakaf.pdf
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/d504a8d3cb88e7dec18868ed226e7416/41841598602.pdf
    • https://amursvoidom.ru/media/files/27714339348.pdf
    • http://adabaskimerkezi.com/upload/file/74407133921.pdf
    • http://adams-gold.ru/archive/image/file/rovalekiluzizaxafa.pdf
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/16073e0d880564---gomamiwiwefusigetibi.pdf
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/c17e017c4f1e68b289e5edab81aafa0e/52301234947.pdf
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/a78aedbb5ab266d9f33b610c7aa3f142/65413501057.pdf
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/aaaa84f1b13f2892beebb3a2eca08085/razaxogitiw.pdf
    • http://afghansolar.com/userfiles/file/29688186013.pdf
    • http://classicalgardenfountains.com/uplds/file/48740662956.pdf
    • https://bechtoldpaving.com/wp-content/plugins/super-forms/uploads/php/files/9d260bfa059a64f48f1af22399177b4b/vakexixu.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_off0000e57e.bin
3db2a439728324dd69794715d75a3a821032ed263cb83cafc1eb9a263a552f30
pdf-font-stream PDF embedded font (sfnt) at offset 0xE57E 16428 bytes
font_01_sfnt_off00011010.bin
4571d94f1cb1a0b4bdb355b975bfcfedc751bdcd4d5823ea2eab8a7f55595a5f
pdf-font-stream PDF embedded font (sfnt) at offset 0x11010 10136 bytes
font_02_sfnt_off000126ec.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x126EC 16792 bytes