Malicious PDF — malware analysis report

Static analysis result for SHA-256 38af16c2663b01d3…

MALICIOUS

PDF

80.3 KB Created: 2021-09-17 16:45:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 5f69da67e29e5c388117cb67e9ac1e22 SHA-1: fc1720296b57c93534fa3df43f8ffd03539eb0c6 SHA-256: 38af16c2663b01d3e9e7e4895b6572226e8b2abe3031c82e77b7956f385d9f44
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs pointing to various domains, many of which appear to be part of link farms on disposable hosting. The ML classifier strongly indicated maliciousness, and the presence of external URIs suggests an attempt to redirect the user to potentially harmful content. No scripts were extracted, but the overall structure and URL distribution are indicative of a phishing or malware distribution lure.

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://crysiq.ru/uplcv?utm_term=y+mail+sign+in PDF link annotation
    • https://cottonweb.net/userfiles/file/varaxopajiwonijevore.pdfIn PDF document text
    • http://www.srijonihealinghome.com/fckimages/file/jekanepoxekowama.pdfIn PDF document text
    • http://relaxzenter.com/uploads/files/59182695514.pdfIn PDF document text
    • http://srihemkuntsahibfgp.org/hemkunt/userfiles/file/73325599007.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/16141c78518c59---darimimove.pdfIn PDF document text
    • https://prolocolidodisavio.org/ckfinder/userfiles/files/kuvenugewiwalenibizolu.pdfIn PDF document text
    • https://www.verimevzabavu.cz/ckfinder/userfiles/files/56257947466.pdfIn PDF document text
    • https://aadhaarretail.com/administrator/imagetemp/file/rivitifunavaduravu.pdfIn PDF document text
    • https://www.hotel-restaurant-plainfaing.fr/ckfinder/userfiles/files/fuximobasi.pdfIn PDF document text
    • http://thesnowmanicecream.com/ckfinder/userfiles/files/nabubukapulutazidubi.pdfIn PDF document text
    • http://briquettemachinery.com/d/files/zonowori.pdfIn PDF document text
    • http://c2r-auto.com/uploadfiles/file/2021090404282573499.pdfIn PDF document text
    • http://aire-limpio.com/img/editor/file/kedakevegunagamorixigoba.pdfIn PDF document text
    • http://ouhkpthaa.org/userfiles/26390538764.pdfIn PDF document text
    • https://stiff.pl/ckfinder/userfiles/files/vulapezamigaxebap.pdfIn PDF document text
    • http://constantemail.com/userfiles/file/1631567405zuzepamapuliz.pdfIn PDF document text
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/e17523d60df2318f874323a83e755650/42389372317.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/041d7b522955d1a5723d4ee958d37dde/42437207568.pdfIn PDF document text
    • http://myblindz.com/fck_user_files/file/62861969505.pdfIn PDF document text
    • https://implantsdentairesdesmoulins.com/upload/editor/file/mijewipogodizij.pdfIn PDF document text
    • https://xn--bren-mgenwil-gcbf.ch/sites/default/files/fck-uploads/file/bofopa.pdfIn PDF document text
    • http://huanghels.com/filespath/files/20210917133037.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_off0000cd80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD80 21624 bytes
SHA-256: d6b26fa765e346f5ac262fd94c61f3fa2cf59f6ba4896feaac1b19b788fa7c9e
font_01_sfnt_off000105ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105EF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E05 9984 bytes
SHA-256: e092e91719fb47f4af8a53b38d9e5fd8c3b1e295715c4003f107cb7068e7f81c