Malicious PDF — malware analysis report

Static analysis result for SHA-256 a39a3891b1c12e71…

MALICIOUS

PDF

82.9 KB Created: 2021-09-06 05:34:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 8cb737387452f8edd5df106f3c27d6c0 SHA-1: f9fc9471ec8642af2baf4054bb81222d7067c8f0 SHA-256: a39a3891b1c12e7110926da1b56e5506357265b40eef08cc198288c6fd2210cb
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users to malicious content. The ML classifier strongly flagged this PDF as malicious, and the presence of embedded URLs suggests an attempt to facilitate initial access via spearphishing. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 5

  • 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://krisoc.ru/uplcv?utm_term=secret+diaries+of+anne+lister+pdf PDF link annotation
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/479197c48951a4cb52d03bed0a35f169/wenadonagejexojapu.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130f671a3595---34176534057.pdfIn PDF document text
    • http://liburnia.pl/userfiles/file/xukodekubiwafemekazajot.pdfIn PDF document text
    • https://vuaship.com/wp-content/plugins/super-forms/uploads/php/files/hvbvr64dd7ooodt6f90s4k348n/76351869124.pdfIn PDF document text
    • https://almoheetmanpower.com/public_html/userfiles/file/numinenojalegam.pdfIn PDF document text
    • https://sealand-pptc.com/userfiles/file/2045890443.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/g5p31n1j57l2so03dnbu96hl5s/42027813232.pdfIn PDF document text
    • http://www.justgiveahand.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607ccb3b7b4b1---dedaradebiz.pdfIn PDF document text
    • https://premiumvipbusiness.com/wp-content/plugins/super-forms/uploads/php/files/dc4637fb202507d56143c0990eb35ea4/3109627998.pdfIn PDF document text
    • http://hillandcunnreunion.com/clients/864369/File/74344332904.pdfIn PDF document text
    • http://cachnhietcacham.vn/Images_upload/files/7424208307.pdfIn PDF document text
    • http://busangh.com/attfile/fckimg/file///20210811151446_1015920539.pdfIn PDF document text
    • https://prestinieurope.com/userfiles/files/6942104347.pdfIn PDF document text
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/160872c705eaef---75508733182.pdfIn PDF document text
    • http://anthonyvienna.com/sites/default/files/file/70819276708.pdfIn PDF document text
    • https://partetesal.ir/data/file/95409966862.pdfIn PDF document text
    • https://lysgaards.com/ckfinder/userfiles/files/kebofoxedagibuf.pdfIn PDF document text
    • https://ayurvedaemart.com/uploads/file/bidapesuji.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/d86ff424634babd54b72bb0382f73f2a/35622414502.pdfIn PDF document text
    • http://savvyais.com/userfiles/file/90883984438.pdfIn PDF document text
    • https://combrooncom.com/contents//files/bixunodanoxalovidikes.pdfIn PDF document text
    • https://www.sadcmedia.com/wp-content/plugins/super-forms/uploads/php/files/b2ug77c8up9g5qjsv9056oi2nv/10628208926.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e0cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0CB 10688 bytes
SHA-256: 2bd4ea01bf04707f83ef2209faf0a6982553ab99a5bd63323876dd9528e87b10
font_01_sfnt_off0000f962.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF962 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011174.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11174 17144 bytes
SHA-256: 5ccffa656c3b923133c89ac34a699b381848daaf22d9aa4b990681a66290abe9