Malicious PDF — malware analysis report

Static analysis result for SHA-256 04c9df8c95b9bf57…

MALICIOUS

PDF

87.6 KB Created: 2021-06-20 10:47:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 44f72ada6a80c42516b0a4a47cfea535 SHA-1: 07fcdd580e10fda66bb10dd7499ac45631ce6043 SHA-256: 04c9df8c95b9bf57e5cfa548d448f6062f71b7ea2ff887a2d9f70000f6d63ba6
236 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it contains a link farm and prompts the user to disable security software, a common tactic to facilitate payload execution. The document also instructs the user to use a password for an archive, suggesting a multi-stage attack where the actual malware is hidden within an encrypted archive.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Security software disable instruction high SE_SECURITY_BYPASS
    Document instructs the user to disable antivirus or security software — unusual for ordinary documents and high-risk in an unsolicited file
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://ankaser.com/userfiles/file/mowusag.pdf
    • http://pvsystreports.com/wp-content/plugins/super-forms/uploads/php/files/7c3h9vt0flhc8l2hf27atjdpq5/48774173349.pdf
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/mejuwunulukisonirax.pdf
    • https://castilloexterior.net/ckfinder/userfiles/files/18313463297.pdf
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/abcnlqq0llh2mi88jmctrf8a76/56769744685.pdf
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16082191cc025f---24438377470.pdf
    • https://lightspec.ca/wp-content/plugins/super-forms/uploads/php/files/b7fd868ab8db587e08d958651a5c7baf/94377070121.pdf
    • https://www.tangelo.no/wp-content/plugins/formcraft/file-upload/server/content/files/16078b9df776cf---72888068709.pdf
    • http://93564497.com/userfiles/fokutu.pdf
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607c83f5cabf8---51802417758.pdf
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160789631e4489---mugura.pdf
    • https://abe-rdc.com/userfiles/file/rovojama.pdf
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160964bdced292---6803657775.pdf
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/8659bac5ca586179435d813a5692d932/rujimapuwipew.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=kmspico+office+2013+activator+windows+10
    • 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://scripts.sil.org/OFL
    • 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_off0001005f.bin
93968383f4ed22fb9d510cf5faccd3fa45b37517250d4ee3741e82028035b2de
pdf-font-stream PDF embedded font (sfnt) at offset 0x1005F 5880 bytes
font_01_sfnt_off00011473.bin
c6e17877cc9e4f05c143de016f86ca434f3c863a42bc1c60304e9df3669eb975
pdf-font-stream PDF embedded font (sfnt) at offset 0x11473 11556 bytes
font_02_sfnt_off00013b50.bin
f267a97a42ed964490c0c36cf8d24d30f5cfc386ee24850e75bb3a4991f11828
pdf-font-stream PDF embedded font (sfnt) at offset 0x13B50 16376 bytes