Malicious PDF — malware analysis report

Static analysis result for SHA-256 aca9a0761b6aeeb5…

MALICIOUS

PDF

77.9 KB Created: 2021-08-15 14:00:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5c32f95c3da655d8b642c027c2c7d3ea SHA-1: 18d353515fc3bbd03eed353c278db2492a89e5b8 SHA-256: aca9a0761b6aeeb5b7dbcd0f599d547e5509e75814b1c897645aed249ba3302b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and is identified as a link farm, with many links pointing to compromised WordPress upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution through these redirected links. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9829

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://cructi.ru/uplcv?utm_term=rus%C3%A7a+alt%C4%B1n+kitap+pdf
    • http://hanleyresources.com/images/zobapozenisivixagukosave.pdf
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/6kkgciqa313ksp5rke0hdkusq2/21725481232.pdf
    • http://silverk.ru/img/lib/file/23475434828.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/da2b9799347962929f5cc043ee5aabe9/tovon.pdf
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/16075a6166ea04---10820053991.pdf
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607610b3c3c4a---77466045303.pdf
    • http://md-servicios.com/userfiles/file/60426900921.pdf
    • http://everest-c.ru/ckfinder/userfiles/files/4288531701.pdf
    • https://seataclightingalaska.com/wp-content/plugins/super-forms/uploads/php/files/d3e16ef7f4416cd8f32dde9ba928b3d2/wosokelilazibamunutopo.pdf
    • http://satit.nrru.ac.th/satit/_Adminis/ckfinder/userfiles/files/dizarejikigiperumowiba.pdf
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ae667198a4---ladaw.pdf
    • http://savitaco.com/uploads/images/files/9239342348.pdf
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607c2ec459856---420041664.pdf
    • http://fkjz.cn/upload/files/2021/07/202107300248532475.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa4f8b73102---55405652690.pdf
    • https://willmarareachamber.com/ckfinder/userfiles/files/76024966466.pdf
    • http://namhungholdings.com/uploads/ckfinder/files/jagexajemubiwuwazajo.pdf
    • https://indacphuc.com/wp-content/plugins/super-forms/uploads/php/files/2j5db1iem5v1i956t5l3h9vfmk/75526444585.pdf
    • https://journeywithmypet.com/ckfinder/userfiles/files/mulewolanolosizokor.pdf
    • http://sinproval.it/userfiles/files/wotuveriwotovezazara.pdf
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b289b4d4ac9---32453323042.pdf
    • https://elitstroycraft.ru/source/file/72692293813.pdf
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/37f182796bec86fd1dfa535079eac41a/dedomizifiwovidukabu.pdf
    • http://dobrasekacka.cz/userfiles/file/23021607055.pdf
    • http://gpn1971.org/clients/a/a2/a25689677492d603657f1241a2a69ea8/File/69603825793.pdf
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/mokexutobux.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_off0000ccdb.bin
b6d50886b2e15cf68cfd78196d88c43a65a8e448253bb46d09cb443809d60764
pdf-font-stream PDF embedded font (sfnt) at offset 0xCCDB 17560 bytes
font_01_sfnt_off0000f853.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF853 16792 bytes
font_02_sfnt_off0001106a.bin
50833c284b331ceda9fdcd9a1a995fd3062705411e86c94152bffb71469d22f5
pdf-font-stream PDF embedded font (sfnt) at offset 0x1106A 10620 bytes