Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8e667d2fd72bbc7…

MALICIOUS

PDF

88.0 KB Created: 2021-07-04 16:11:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 67b92792999fae21a53d981d8cc10474 SHA-1: c400ffaf7684f9e76aac35e4cf04ae2093f4b285 SHA-256: a8e667d2fd72bbc7a460a5c745ca59f947cf5f1afcada3c8008d0015dc7a0f44
184 Risk Score

Malware Insights

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

The PDF contains multiple links to disposable hosting and compromised CMS upload storage, indicating a link farm designed to distribute malicious files. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body, though heavily obfuscated, contains metadata from wkhtmltopdf, suggesting it was generated programmatically to present a lure, likely for a fake download, which is a common tactic for malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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
  • 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://bursac.net/userfiles/file/17178866222.pdf
    • https://alajuusa.ee/media/contents/file/11593799249.pdf
    • http://abcbyspu.com/ckfinder/images_store/files/redadoka.pdf
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/k9bupa1u5543n96icoqlg6r5dn/mufudijez.pdf
    • http://smflow.in/admin/uploads/file/bobetes.pdf
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16079226e096e0---19906566238.pdf
    • http://sacoorhealth.pt/site/upload/file/pidolasilimerule.pdf
    • http://jnnycc.org/userfiles/file/43323036281.pdf
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/0qjtmohgvhu9vdkvjfgjim6t5l/63422763653.pdf
    • http://abovomedia.hu/_user/file/tidirisimeguveg.pdf
    • http://barcelonahotel.vn/UpLoadFile/file/18108832810.pdf
    • https://giorgiosantinelli.it/file/bofosulutexubadokefinina.pdf
    • http://penzionriverside.cz/files/file/16153674690.pdf
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/16092eb5e99d53---ditavevorofapujumafum.pdf
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/cce88c0a9a548c3df45454c9d5290886/61217077954.pdf
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aca8284d374---fenafavuvatudatupek.pdf
    • http://abacusnancy.com/userfiles/file/11042897025.pdf
    • https://alihuata.com/userfiles/file/49789848059.pdf
    • http://doubletroubels.com/wp-content/plugins/formcraft/file-upload/server/content/files/160722df54905c---30655859799.pdf
    • http://canadanur.com/resimler/files/13487030667.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a21b4196b97---49672238142.pdf
    • https://aravlicraft.com/cmsCart//upload/file/2841320998.pdf
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/16079f52e36022---folurura.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=opm+songbook+with+guitar+chords+pdf+free+download
    • 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_off0000eebb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEBB 16792 bytes
font_01_sfnt_off000106d2.bin
6e29a64b49a36377448d9d2e614f84e23757ea3b69dced6cca94fbfe36513e1c
pdf-font-stream PDF embedded font (sfnt) at offset 0x106D2 11508 bytes
font_02_sfnt_off00012190.bin
38aa43c705323a1368b02d3fe635095654d85b2479ba5dd07c5aad0c93970f8e
pdf-font-stream PDF embedded font (sfnt) at offset 0x12190 18360 bytes