Malicious PDF — malware analysis report

Static analysis result for SHA-256 21afeaa8c475e003…

MALICIOUS

PDF

86.9 KB Created: 2021-08-17 18:27:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 9b7a1de071a595bb6479d3abc6036222 SHA-1: 16b9a5e732b858facca61792290056fd8cffbe34 SHA-256: 21afeaa8c475e003e84da0762f947cdea143cc9bc740a14b9707e67bc0de46da
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The file functions as a link farm, containing numerous external URIs that point to various websites, some of which are hosted on compromised WordPress upload storage. The primary purpose appears to be redirecting users to potentially harmful content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://archism.ru/uplcv?utm_term=akademia+pana+kleksa+audiobook+ca%C5%82a+ksi%C4%85%C5%BCka+jan+brzechwa+chomikuj PDF link annotation
    • https://bonacorsi.it/file/86410470911.pdfIn PDF document text
    • http://carroll1975.com/clients/4/4e/4e2b018d07aaa5a30c3e4fca1c7a8df7/File/tujonogutalujonuf.pdfIn PDF document text
    • http://spencerrandlefamily.com/clients/864257/File/dezamuponumuxuto.pdfIn PDF document text
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/bf5bb543fc968d297b75aeb0a96e851b/6292017012.pdfIn PDF document text
    • http://www.parkwaytransplant.com/media_upload/upload/files/4739072525.pdfIn PDF document text
    • http://www.darvidproperty.com/news/file/59057837552.pdfIn PDF document text
    • http://hanboo.cn/Uploads/file/2021051705123670554.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16083441d5b9ee---motimajijimaw.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/eccc9532f358ded65b5e3b859699fc12/vuzamuleleledulutaj.pdfIn PDF document text
    • http://skupka54.ru/upload/m/jaxibeboraxefaboziwisow.pdfIn PDF document text
    • https://him-home.ru/wp-content/plugins/super-forms/uploads/php/files/0a1c1855f9686ab1fb9083bee06fdf66/kevopa.pdfIn PDF document text
    • https://resttour.com/images/userfiles/files/15285066086.pdfIn PDF document text
    • http://eau-msu.ru/ckfinder/userfiles/files/31586779837.pdfIn PDF document text
    • http://dailymaydemtien.com/userfiles/files/57566466059.pdfIn PDF document text
    • https://yesilkoyluleriz.biz/resimler/files/sukotabevolusonufi.pdfIn PDF document text
    • http://gilendor.cz/userfiles/file/kipusajuzapelitikuv.pdfIn PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/dc5a48b31b1b384e43304ca9b15b4b00/zusugemuma.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/16079d5a62955a---26111920962.pdfIn PDF document text
    • https://insolite.lu/img/userfiles/files/xibirezezigaziwasugek.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f8ed12eb49---9720959291.pdfIn PDF document text
    • http://menloathertonhigh1980.com/clients/6/6f/6f83464fe0b13873896cace574d4baa5/File/56544549394.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/16074fa71a39f5---fidika.pdfIn PDF document text
    • https://noddy.nu/images/file/tawofelorebifuzonebeda.pdfIn PDF document text
    • http://sporteambiente.it/ckfinder/userfiles/files/41093215764.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e7a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7A6 18992 bytes
SHA-256: b95a48a5aacfa889fa8683ab3e07a847491201f45f9084c45771476da0d2b749
font_01_sfnt_off000116ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116AB 11684 bytes
SHA-256: 939e6db79122c79d333f922e6b633ba9dbfd8adce36ba9bb9ab0afc8e465add9
font_02_sfnt_off000131ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131AE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1