Malicious PDF — malware analysis report

Static analysis result for SHA-256 12da31efc68c52c8…

MALICIOUS

PDF

82.2 KB Created: 2021-09-09 10:43:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 993012bcdaedea881ea51e6d663c94c2 SHA-1: e18dbacd4a1bdc8cb62c7f15fe34aa21475ab09d SHA-256: 12da31efc68c52c83e98c4b0a803d1cb69e8e0c8b857ec0d93767050084b70b6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document, potentially leveraging embedded JavaScript for further actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://nomylo.ru/uplcv?utm_term=docx+viewer+portable
    • https://orig-shop-gsm.ro/ckfinder/userfiles/files/7064208847.pdf
    • https://derfo.info/resimler/files/94248366698.pdf
    • https://birotex.rs/images/files/35808309051.pdf
    • https://valerart.com/ckfinder/userfiles/files/dekolatagaso.pdf
    • http://jiendurancecoaching.com/ckfinder/userfiles/files/15222785480.pdf
    • http://bukharageorgia.com/sites/default/files/file/vojonunapikirab.pdf
    • http://www.ondebiz.com/userfiles/file/poridosejezonigekosa.pdf
    • http://emanuelarombiarchitetto.eu/userfiles/files/26714731587.pdf
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16139b363c07bf---pategabalirulawoposulu.pdf
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/51ccbjamn4cfdpap0a2jq3lklj/weweveba.pdf
    • http://twtipa.com/upfile/files/2021/09/07/nizibinisepovesok.pdf
    • http://sensor4you.com/fckeditor/editor/filemanager/connectors/php/fckeditor/upload/202109/file/4410699922.pdf
    • http://swatimishra.in/uploaded_files/userfiles/files/38280819403.pdf
    • http://missteenqueenuk.com/userfiles/file/35013000863.pdf
    • http://cjpharmtech.com/upload/files/nukiwozedatez.pdf
    • http://atel-j.nl/uploads/files/rogamoradogujesuf.pdf
    • http://dietaltop.com/userfiles/files/47390077765.pdf
    • https://atiksigorta.com/files/mowonobebosuxelov.pdf
    • https://sukienmiennam.com/userupload/files/fasiga.pdf
    • http://kortennis.co.kr/B/ck/ckfinder/userfiles/files/13036442512.pdf
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/1a707dd4fe6a72d79a9c33ab0a99250f/jidufawekuvudubi.pdf
    • http://styropapex.pl/userfiles/file/lesofepemijetapu.pdf
    • http://www.yankey.com.tw/demo/public/editor/ckfinder/upload/user_upload/files/wifog.pdf
    • http://ymjgolf.com/file_media/file_image/file/66525163915.pdf
    • http://xn--z92bzy85x.com/userData/board/file/75298475882.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_off0000dc61.bin
11859c15fce6df98dca7ba705db573f0e8547172f0732e3a029d1cca4653465d
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC61 17916 bytes
font_01_sfnt_off00010af3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10AF3 16792 bytes
font_02_sfnt_off0001230a.bin
fb7ab5681716e19f41bf47f840756094191bb7cedd4d00c63e7dac70e095dd8a
pdf-font-stream PDF embedded font (sfnt) at offset 0x1230A 10492 bytes