Malicious PDF — malware analysis report

Static analysis result for SHA-256 36023cf14eb0eaa1…

MALICIOUS

PDF

79.8 KB Created: 2021-09-21 01:00:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 61f2b5534bb1fc3f97a78081e8cdafdf SHA-1: ab2219a0d3d97cf9b54b665ce0e3a439c01ad590 SHA-256: 36023cf14eb0eaa1a2e37663050832e6aeab8cb7dbf15dcdcc95078c57b5a716
156 Risk Score

Malware Insights

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

The file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Static analysis revealed it functions as a link farm, with numerous embedded URLs pointing to PDF files hosted on various domains, some of which are associated with compromised CMS uploads. The presence of these links suggests an attempt to lure users into downloading further malicious content or visiting phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 http://chiangmaicharmingtravel.com/ckfinder/userfiles/files/fawebidigavinawenunonona.pdf
    • http://mbfeed.vn/upload/files/bupizupapugitogadozukig.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161431de001844---30957791298.pdf
    • https://temahr.hr/files/lizojisur.pdf
    • http://generaldistco.com/images/file/17428110838.pdf
    • http://erimti.com/userfiles/file/1239013929.pdf
    • http://tattooindex.nl/images/uploads/xusajetafukijibetax.pdf
    • http://phongthuydotho.vn/upload/files/95655104779.pdf
    • http://theexplorerthai.com/userfiles/files/18869731733.pdf
    • https://asiantms.com/ckfinder/userfiles/files/16080191929.pdf
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140ba3d44688---55345015523.pdf
    • https://malayalamfoundation.org/admin/my_files/file/bemofu.pdf
    • http://abyss.sk/userfiles/file/25905875878.pdf
    • http://flemingdecal.com/uploads/assets/file/47438163285.pdf
    • http://prestopc.it/upload/file/namer.pdf
    • http://tce.vn/imagesflashupload/file/78990637011.pdf
    • https://varida-tech.com/ckfinder/userfiles/files/2411819687.pdf
    • http://cavusofis.com/images_upload/files/nuzamuraxinepas.pdf
    • http://wccflooring.com/userfiles/files/81865577098.pdf
    • http://shopsuathientu.com/uploads/userfiles/file/23067059736.pdf
    • http://agama-rc.com/upload/files/gudokefawovolopirora.pdf
    • http://americasbestwingsbeltsville.com/uploads/files/widifedupafa.pdf
    • https://tamtam.com.ua/wp-content/plugins/super-forms/uploads/php/files/9023adf2a8fad63ffb12465fe5eccec7/gepis.pdf
    • http://exms.fr/sites/default/files/file/1183580876.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=transfer+calendar+from+iphone+to+android
    • 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_off0000d1ae.bin
00b3022c3f243a9eab590405824f4eb2619651ad13a7a3a8f3119b0c63f8228a
pdf-font-stream PDF embedded font (sfnt) at offset 0xD1AE 10848 bytes
font_01_sfnt_off0000ea7f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA7F 16792 bytes
font_02_sfnt_off00010291.bin
9d89bf02505e0cdc2e53ec93b841bf1b2f5e4aad2a8a26faba894c34a993a2c9
pdf-font-stream PDF embedded font (sfnt) at offset 0x10291 18036 bytes