Malicious PDF — malware analysis report

Static analysis result for SHA-256 36de90d10d8c7339…

MALICIOUS

PDF

76.3 KB Created: 2021-08-12 06:28:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4f8936db7edf1aedd55b6c30c9fb5b14 SHA-1: 19c2684d7b111e6144a75b4709cbaecd5616c1dd SHA-256: 36de90d10d8c73398f808483bebe42828e073e450df1e1abf0b9f94be01445b2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external URIs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16111a3d504b96---buturoxabosozikelotojij.pdf
    • http://9262895.ru/ckfinder/userfiles/files/44022033339.pdf
    • http://gzky.cn/dubeite/ckfinder/userfiles/files/20210610_194158.pdf
    • http://lightningriskassessment.com/ci/userfiles/files/83677024251.pdf
    • http://esipro.fr/userfiles/file/34186086876.pdf
    • https://yuktogel.com/contents//files/zelelunitelaxezexola.pdf
    • http://impactpluslearning.com/ckfinder/userfiles/files/8397028007.pdf
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/e1676edcf340dd03799d6299cff29250/34379488924.pdf
    • http://iehyun.com/editorupload/file/71630758309.pdf
    • http://zelene-centrum.cz/webpagebuilder/ckfinder/userfiles/files/72957393579.pdf
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606ccc0b9bf3d---75369841409.pdf
    • https://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/70aeac5cea520247f316de3bd0fe3e06/fukinixozir.pdf
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/160b44ac85a88d---vegunedasexu.pdf
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/h9u8hf5jk6e0p40lhfn8hu3g81/89724110764.pdf
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/16106a48ae4657---60838561556.pdf
    • http://wecans.net/_UploadFile/Images/file/17438462260.pdf
    • http://bacvietexpress.com/upload/userfiles/files/miredeluragixaxaro.pdf
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607f29da7810b---47387889497.pdf
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096a16705909---tolobimepe.pdf
    • https://ottopianos.nl/files/5211008183.pdf
    • http://cerezolorente.com/files/cerezolorente/_repo/file/13617137391.pdf
    • https://j26clean.com/upload/files/fovetilakafud.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=suma+y+resta+de+n%C3%BAmeros+enteros+ejercicios+resueltos+pdf
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/8ebee57061efe1309eef0d986d2e18eb/5548895605.pdf
    • 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_off0000c61e.bin
9f91616c6d93b1d23b69e81a39003a4d0c5410aefefcbe61b4343fb3d6986cf8
pdf-font-stream PDF embedded font (sfnt) at offset 0xC61E 16040 bytes
font_01_sfnt_off0000ee34.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE34 16792 bytes
font_02_sfnt_off0001064b.bin
d7ddbd722736b1cad7b4ac2f76d6d210d5cff24bc3a164dbfbc0df47e1b5ff35
pdf-font-stream PDF embedded font (sfnt) at offset 0x1064B 11316 bytes