Malicious PDF — malware analysis report

Static analysis result for SHA-256 35c2f1b66564d2a5…

MALICIOUS

PDF

78.4 KB Created: 2021-09-17 21:31:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d3b05012c3e730eb0e10dbc19e28cc64 SHA-1: ba172146cfa23031b77487c4dc1753160c2b4d6b SHA-256: 35c2f1b66564d2a5b19884795d860c2fe58a93a0871d780d379e8b01e7fc5af2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of external links, many of which point to compromised WordPress upload directories or other potentially untrusted hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery through these links. The document body is unreadable, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

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 https://reazfarah.com/ckfinder/userfiles/files/36121554643.pdf
    • https://www.meditech.cz/ckfinder/userfiles/files/kijesopuwepiwelarinokot.pdf
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/ac65f6d70994436f43941a3ca2880e3d/xiluwexixipaxugufefan.pdf
    • https://asi-filter.pl/files/file/32499041612.pdf
    • http://noticiascgnews.com.br/ckfinder/userfiles/files/16862612018.pdf
    • https://tsafar.ir/basefile/tsafarir/files/99121584165.pdf
    • https://ikincielinmak.com/upload/ckfinder/files/zazabo.pdf
    • https://artenika.pl/fck/file/12718655056.pdf
    • http://silver1979.com/upload/file/baxas.pdf
    • https://clinicscrm.com/img/files/nuwebol.pdf
    • http://dsraxys.com/uploads/40623938330.pdf
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614390ea9b419---4894061291.pdf
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16141274b3bf57---46093173933.pdf
    • https://agentcctv.com/userfiles/file/lirikidizebuxewufuxaba.pdf
    • https://abzesolar.com/uploads/files/34635079992.pdf
    • http://immobilier-valence-agen.com/userfiles/file/69609606099.pdf
    • http://kirche-treuen.de/UserFiles/File/nokigabug.pdf
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613562eb058cf---napexupuzage.pdf
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/8na3bihf4sufbf4iaau2o9ka8s/49783011426.pdf
    • https://ekoelprom.pl/public/images/editor/file/risutu.pdf
    • https://cashcruis.ru/wp-content/plugins/super-forms/uploads/php/files/cf5b78b312ba2213cd6bdaf581e79de5/suvajibamekexositulole.pdf
    • https://artinterior.bg/userfiles/file/rojuvix.pdf
    • http://nuuts.mn/uploads/assets/bezevali.pdf
    • https://lolakarimova.uz/ckfinder/userfiles/files/pufexemuxojikatagirirel.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=open+gallery+of+my+phone
    • 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_off0000cf72.bin
1cd53f5c15457014b563e0a0620acb25f145e08b9b7c5a3c49bbe19357aceb90
pdf-font-stream PDF embedded font (sfnt) at offset 0xCF72 17464 bytes
font_01_sfnt_off0000fc26.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC26 16792 bytes
font_02_sfnt_off0001143d.bin
5e4397c8dad458977965bbf30574f9f14e1d4fea8c36a3c00c2a1d40e3dc5431
pdf-font-stream PDF embedded font (sfnt) at offset 0x1143D 10584 bytes