Malicious PDF — malware analysis report

Static analysis result for SHA-256 b286c3a686cd0cf0…

MALICIOUS

PDF

76.0 KB Created: 2021-08-13 11:19:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 82ebbcd72566f75297622d491621438d SHA-1: 115c81e4d036a9d6eff53a71e8764368efced598 SHA-256: b286c3a686cd0cf088fc463a63da55be54e04b79d9aaa0c26e1df07b0a2b1fa1
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous compromised WordPress sites, a common tactic for phishing or distributing further malware. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of multiple external URIs and link farm heuristics confirms the primary function of this document is to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://xn----7sbbjg7ctfs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0bb4d1296085eb711ca8d1a71fbe6b19/zikivinekifexitilukovu.pdf
    • https://wulf-sanitaer.de/wp-content/plugins/super-forms/uploads/php/files/91er8hd004ch74qbm6du5sb48i/zupuzusoxe.pdf
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a46844d2ca0---lerefesupimodep.pdf
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/vl3b0pe5h4ufs5kn3cocpn9uli/1515034459.pdf
    • http://nowator-zpu.pl/userfiles/file/21201863747.pdf
    • http://2ds-creations.fr/userfiles/file/36849286777.pdf
    • https://zemiigori.com/uploads/file/16346386193.pdf
    • https://alnahamgroup.com/userfiles/file/64060082460.pdf
    • http://kirakuramenandsushi.com/uploads/files/piperidojumixena.pdf
    • https://chung-pei.com/userfiles/file/76671541923.pdf
    • https://feng-shuiworld.com/userfiles/file/26641522880.pdf
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160763da12f4be---87542346102.pdf
    • http://zzquansu.cn/d/files/98876051936.pdf
    • https://ngaa.org.au/application/third_party/ckfinder/userfiles/files/33886876179.pdf
    • https://net-mex.hu/ckfinder/userfiles/files/bobep.pdf
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1607a26c10133b---29428183171.pdf
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/fh39ngb9jbbq1irdgtad4ac9tp/nuzabibanoxujebivefum.pdf
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/c1413a9c6f4eafa55982ae7237012cd4/40282489083.pdf
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c05af183c5e---tinijobonovuxewoxizak.pdf
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1607975f92ddb0---73250400768.pdf
    • https://businessservicesuk.com/userfiles/file/69699389773.pdf
    • http://czdashan.cn/uploadfile/file/2021080809012973499.pdf
    • https://kochitaxirental.com/ckfinder/userfiles/files/24501698384.pdf
    • http://alpha-th.com/userfiles/file/75019086956.pdf
    • https://limpiezasinasel.com/userfiles/files/52247844504.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=vocabulary+workshop+level+b+unit+11+antonyms
    • 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_off0000c749.bin
cd25ac4293b279ef71382f4eafa56bbc022d53cb94d4e8e4074ced3d5d3b3884
pdf-font-stream PDF embedded font (sfnt) at offset 0xC749 16016 bytes
font_01_sfnt_off0000f074.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF074 16792 bytes
font_02_sfnt_off0001088b.bin
ec1c30408bcccc3c4f96882b7997ecb707b7639773af37832b34860ac06f6c4f
pdf-font-stream PDF embedded font (sfnt) at offset 0x1088B 11256 bytes