Malicious PDF — malware analysis report

Static analysis result for SHA-256 84397a3d7ac941c4…

MALICIOUS

PDF

77.0 KB Created: 2021-09-16 15:10:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9a3fcda026eb00c5012efc47d77ab78d SHA-1: 9dc74f968ac53df5af9eab4eb9f6a02716a966dc SHA-256: 84397a3d7ac941c4a37ab53b4ca34142198373aad6f4b0bf61b504a357cfda4b
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs pointing to other PDF files, many hosted on compromised CMS uploads or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. The presence of multiple external URIs and link farms suggests an attempt to obscure the final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://uangraja.com/contents/files/geponujoluzavugeluzadana.pdf
    • http://gamax-moto.cz/data/dokumenty/57573607039.pdf
    • http://toyotarent.tw/FileData/ckfinder/files/20210916_AFBE71FD10436F39.pdf
    • http://metalltechnik-kutschi.at/28617412047.pdf
    • http://rentappli.com/tinymce/jscripts/tiny_mce/plugins/phpimage/phpimage/upload/images/file/40300703985.pdf
    • https://resonanceacteurs.nl/userfiles/file/59609193075.pdf
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16141a9d16a7fb---lilowopedapatabu.pdf
    • http://xn--2-140-swe8h.xn--p1ai/files/jomabozusif.pdf
    • https://a-guskov.ru/uploads/files/87895064180.pdf
    • http://julianina.dk/upload/file/pokekolelunik.pdf
    • https://galaxytraining.examinationonline.com/files/fagotarogatan.pdf
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141968819607---94575464112.pdf
    • https://erdemlerkoleji.com/resimler/files/13842486170.pdf
    • https://aynadakikemalizm.com/resimler/files/vonuk.pdf
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f4da4aa21a---pivawikanezod.pdf
    • http://lesen-und-schenken.de/userfiles/files/nefirememepuwelizi.pdf
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/5824df9aaff0893ac77e2dd7d67d5887/xegugubowamorar.pdf
    • http://specimport.by/files/files/lunugunafoni.pdf
    • http://xn--80aaaaaikdebj9ccf1ayja1b5a3q.xn--p1ai/ckfinder/userfiles/files/mofijonemikamilagug.pdf
    • http://lawfirm.vn/MINH/user_files/file/74524827244.pdf
    • http://www.oe.com.tw/ezadmin/ckfinder/userfiles/files/74236961881.pdf
    • http://elfuklid.cz/foto/Image/file/xanimepuzis.pdf
    • https://didacostruzioni.it/userfiles/file/finowusenokeladifoduvoj.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=harrison%27s+gastroenterology+and+hepatology+3rd+edition+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_off0000c126.bin
cb471abec0529e43550f69e5ad9223810a11d06c6a81e9aad8887d4ef1901f9e
pdf-font-stream PDF embedded font (sfnt) at offset 0xC126 11088 bytes
font_01_sfnt_off0000dac0.bin
ae9472202353eda9c70d0376bde43c5491f8027c9ee80b7b53ca7975bab4acf5
pdf-font-stream PDF embedded font (sfnt) at offset 0xDAC0 19732 bytes
font_02_sfnt_off00010d81.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D81 16792 bytes