Malicious PDF — malware analysis report

Static analysis result for SHA-256 523c17ee6f160c29…

MALICIOUS

PDF

91.6 KB Created: 2021-07-17 20:31:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9c45ea571141b89e120b9ca02c5fa352 SHA-1: 926948edcb8d0ba694d1fb2a11d9fb00d908b602 SHA-256: 523c17ee6f160c292e943fbe4a4d8aa3a84d0bbd2d014db0f765434df0cc61a4
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to compromised or disposable hosting domains, a common tactic for phishing or distributing further malware. The ClamAV detection and ML classifier strongly indicate malicious intent, likely exploiting PDF vulnerabilities to redirect users. The presence of multiple PDF-specific heuristics related to link farms and compromised CMS uploads reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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 http://abwmercury.com/uploads/files/52375256197.pdf
    • http://www.hydro-tg.pro/upload/file/dumevivoniwiba.pdf
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1608de892cc882---netagofubibixaw.pdf
    • http://sghscsjamarai.org/guruhargobind/userfiles/file/navotuwobomimufogipab.pdf
    • http://princeton1959.com/clients/863834/File/gevexenovamomovirat.pdf
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160994310e0ff4---36852994991.pdf
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/8cf0293df0e41e013a0cb9714b5376ac/zejutozomatuworowelafoga.pdf
    • http://letresorellebio.it/userfiles/files/17631110729.pdf
    • http://beergolfers.com/blog/images/file/tofejefatumizikawuvuxotub.pdf
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba6bc5b024e---tumese.pdf
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160798cae67d99---vawidibut.pdf
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160c18b091e954---36005094277.pdf
    • http://cutskytools.com/d/files/20967406447.pdf
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4782ee04c7---timafukezekidabujagi.pdf
    • http://4998horo.gmmwireless.com/contents/files/48628351445.pdf
    • http://kipia-nn.ru/userfiles/file/wilararujupaj.pdf
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/fvb789el6v900kt0qm92bf4000/fepobivalo.pdf
    • https://deltagroup.bg/uploads/file/71028445146.pdf
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba54898df92---34115034374.pdf
    • https://benchmarktransitions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160811f47cc270---tepasaburijubinaj.pdf
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/8862646922e3a12aa8da966788523c73/56008681223.pdf
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/38f1dc1f92df1f4113c6e3303653249c/50089454358.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=act+april+2019+form+z15+answers
    • 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_off0000f6f2.bin
8d17d2edf93d2ca37c3d12bcc1804c5abaf6939ae0f8810e3b7d1f62cc0208ea
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6F2 11364 bytes
font_01_sfnt_off000111f1.bin
7d3bb5648926f1f50632312f064eff513fff03af76eaa5f78b9f314921b1aaa8
pdf-font-stream PDF embedded font (sfnt) at offset 0x111F1 21400 bytes
font_02_sfnt_off00014901.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14901 16792 bytes