Malicious PDF — malware analysis report

Static analysis result for SHA-256 341b5fea8f98cbd9…

MALICIOUS

PDF

86.0 KB Created: 2021-09-04 22:36:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3b779b7f0c272db66741788773ff001e SHA-1: 2a437d19b257ecb3e1ce9c2eb41a79db76c3cf93 SHA-256: 341b5fea8f98cbd9478a8327298f7283c1517d3882bd1bb5461ea9f4d3f21fd7
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and links to compromised CMS uploads and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://queure.ru/uplcv?utm_term=multilayer+perceptron+algorithm+pdf
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/bf56d798d236145ae344b11bc324c7fa/67600419023.pdf
    • http://kristiankutschera.de/userfiles/file/3702132727.pdf
    • https://exporoaster.com/app/webroot/files/images/pages/files/zenogu.pdf
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610d9bfde9f90---19618069137.pdf
    • http://yamamatoen-wanwan.jp/ckfinder/userfiles/files/50221313781.pdf
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c5ff6b5545---wolurimabume.pdf
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1607e0e495a853---raboxisenipafobeniniz.pdf
    • https://lawyerupsmart.com/tempimg/file/rerejaterexomamuponugegek.pdf
    • http://drprdesaihospital.com/uploads/65480315243.pdf
    • http://sensi-leszno.pl/userfiles/file/lanejejurujasoz.pdf
    • http://www.syrahresources.com.au/application/third_party/ckfinder/userfiles/files/14498320753.pdf
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/fdebe12909f27bebca9814ea246dc86c/lumitofijudunugupupexunu.pdf
    • http://donaldbermanmaimonidesgolf2020.com/clients/0/0d/0d43fbb8ff91cab41fa1b056c0d912a9/File/48006869800.pdf
    • https://advantagelic.com/singhania/downloads/file/giwonepumawida.pdf
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/c15b34b2bbcf416ccc0b136368a09f13/69961652030.pdf
    • http://adabaskimerkezi.com/upload/file/47034927428.pdf
    • http://for-rent-antwerp.com/wp-content/plugins/formcraft/file-upload/server/content/files/160716c3a41403---1808970455.pdf
    • https://bestofbucerias.com/upload/file/rokusu.pdf
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/9b518b84d5dd57d8e5d0c0c4056b6199/dibazifakuzer.pdf
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160885d8eda30b---lebivada.pdf
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/52cffb18dbe0ef4ca38cee7eabde7a03/peramitalurabunijetimeme.pdf
    • http://mofrantech.com/userfiles/file/17409004444.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_off0000e785.bin
4446e70c65620a86bb6363df0a54511a957cc79f7457c08b1dc4131242626a5e
pdf-font-stream PDF embedded font (sfnt) at offset 0xE785 11108 bytes
font_01_sfnt_off00010103.bin
fff2e35a3558a9bd5967a4e8889732aef42f225f60dbec1f260caad8efad1f1b
pdf-font-stream PDF embedded font (sfnt) at offset 0x10103 18916 bytes
font_02_sfnt_off000132a1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x132A1 16792 bytes