Malicious PDF — malware analysis report

Static analysis result for SHA-256 283757c93efecd2d…

MALICIOUS

PDF

87.9 KB Created: 2021-07-02 09:01:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b2c685bf220fa7a3c69d06cf1d735064 SHA-1: 025368c11e661c90b7205823dfd326cf8a055bba SHA-256: 283757c93efecd2daa600f87d78a59ef2717e10dae7a49e9078984968ab78cbd
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with many URLs pointing to compromised WordPress sites hosting PDF files. These links are likely designed to lure users into downloading further malicious content or visiting phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c93975c0679---68968017392.pdf
    • http://waltwhitmanclassof1965.com/clients/c/cc/ccbfa8a87e297cd67510599b8aebcb74/File/9289110492.pdf
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/dj4s5nqg4mm9m8cls7f2crjhgp/89534710002.pdf
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608aced3c4e94---funowenuxarabemalusur.pdf
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dfa7d2bb2a---14213111687.pdf
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a03afbbce3d---xusazi.pdf
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/nitj0ldv710smid1m0640kuoo0/15425260765.pdf
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160952c2ee3950---dixatubufu.pdf
    • https://nikosdimos.gr/userfiles/file/tinavasotuketiwigu.pdf
    • http://elonsummerstorage.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5f614430f0---xatap.pdf
    • http://luatsuphutho.com/upload/ck/files/17796433378.pdf
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/35912a682511a6ac2e3f3f0198410f6f/29263404411.pdf
    • https://wpsqld.com.au/wp-content/plugins/super-forms/uploads/php/files/6186811ec188141bd89d3c6dbbfc9666/gudaberuman.pdf
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/b6874f0651c0342f595bc2c33d589e52/98998586555.pdf
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/16099e5cc77690---nanizomokopotifakizu.pdf
    • http://www.logomarcanet.com/userfiles/file/kaniserinamebedinazetemi.pdf
    • http://sushrutproctology.org/ckfinder/userfiles/files/18917195817.pdf
    • https://www.mysmilestudios.com/wp-content/plugins/super-forms/uploads/php/files/5a40e1bd29ad04a48a9d124b3a0e254e/15803490247.pdf
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160952fc45ec59---xijekuxapukogar.pdf
    • https://attack.lt/images/files/58731688159.pdf
    • http://prime42.ru/userfiles/files/benoludeli.pdf
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/d374ea675938936b93b9e5ce0febb91c/zozipewavopetigala.pdf
    • https://www.idahomedia.com/wp-content/plugins/super-forms/uploads/php/files/aecd36b26e5debc4f59d4b977a7ed8bc/46061874894.pdf
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/t5schoci81jl34gq2q64vmf11u/bovevurofogokezu.pdf
    • https://circolodelpistone.ch/userfiles/file/labokonafisexisexu.pdf
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c24627c779b---21905704831.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=love+of+sister+and+brother+quotes
    • 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_off0000f53e.bin
def7bdbdd9beb7736e9c4def0e9f397ee4a51830046245a341be3f13263daade
pdf-font-stream PDF embedded font (sfnt) at offset 0xF53E 17096 bytes
font_01_sfnt_off0001216c.bin
5083d9518a642628d984e0013f03c5ca30d79b056b64edc8193e925a846e346e
pdf-font-stream PDF embedded font (sfnt) at offset 0x1216C 10816 bytes
font_02_sfnt_off00013a24.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13A24 16792 bytes