Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc4c8caef5a43394…

MALICIOUS

PDF

81.6 KB Created: 2021-07-07 09:27:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c4e95a14b1f0f692c329da47e9a7a0ac SHA-1: 90c4de694dbfffb6a0a4f4629134094ed7d526e7 SHA-256: bc4c8caef5a433941758d1e37561bc08a922ed142c046c6ca09cabfa2ff2ce27
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to numerous external URLs hosted on potentially compromised or disposable domains, which is a common tactic for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it is designed to exploit user interaction to navigate to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 https://wastran.ru/uplcv?utm_term=icd+code+for+dry+eyes
    • http://nuestratierrapremios.com/campannas/file/32541519158.pdf
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/c6f2c6d9baf4fbe049462e540daa60a8/lifesa.pdf
    • https://alianzatours.com/imagenes/file/52070086109.pdf
    • https://0900107678.com/upload/file/86202231297.pdf
    • http://elma1.ru/!upload/files/68729265048.pdf
    • https://teenvolunteerdallas.org/wp-content/plugins/super-forms/uploads/php/files/385d0af0e91d7fcfed111860c88d2ea9/zosolubixokop.pdf
    • http://csc-0898.com/userfiles/file/20210628094727_e7cy25.pdf
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/5cfq5li4eqat2b7emnhmkd4f53/kozevoloxediderepev.pdf
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e19ff45996a---21967563407.pdf
    • https://alternatifhirdavat.com/upload/ckfinder/files/pevujejiwotaj.pdf
    • http://brandnewgoods.net/userfiles/file/56759303669.pdf
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8dd1b31202---72858469274.pdf
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/ef0c3efc07b48dfc16d6cef44eb21994/76505962417.pdf
    • https://am-system.eu/ckfinder/userfiles/files/61843583874.pdf
    • http://paradisoseminatrici.it/userfiles/files/99525135821.pdf
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160aa9fe9273ed---43800747710.pdf
    • https://vayamcs.com/content_files/files/wasuwesenufolepovod.pdf
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/16081a9f73f47f---sefuxonovexoko.pdf
    • http://burmeseburmilla-allevamento.com/userfiles/files/74347223149.pdf
    • https://iamtimeshare.com/userfiles/file/rivezuwivekubamoribani.pdf
    • http://beachfirebrands.com/userfiles/file/3410563934.pdf
    • https://tomorrowhubs.com/upload/users/files/bevupakoxutopi.pdf
    • http://lovewhereyoulv.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/7ff71ba10fc5bfebc1cc3eada2f00a86/kufuzeniz.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_off0000de17.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE17 16792 bytes
font_01_sfnt_off0000f62e.bin
7d2868fcaf7d177eab0ed2db43d7302324bbbd76396cd3b108b9ef8bd559775e
pdf-font-stream PDF embedded font (sfnt) at offset 0xF62E 10032 bytes
font_02_sfnt_off00010c98.bin
60e25afdfc5caf573d03c4aadfb2aeec65d4cafdbcfb6449b37f64820cf04270
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C98 16552 bytes