Malicious PDF — malware analysis report

Static analysis result for SHA-256 8bba9f78f89a5e14…

MALICIOUS

PDF

68.4 KB Created: 2021-09-26 21:23:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 6244bcdc3f801454545ed61fb143cc3d SHA-1: 32a47b13d4c7c43d67608f8f4c2168293d9d2878 SHA-256: 8bba9f78f89a5e1460c97058bb95b6f8f83b09334c129a59b805e9477f1e5097
164 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and numerous external links, many pointing to compromised or disposable domains, suggesting an attempt to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and the URL with 'utm_term=upgrade+windows+8+to+10+free' indicate a phishing or social engineering lure. ClamAV detection and ML classification confirm the malicious nature, likely involving the execution of a second-stage payload via the embedded JavaScript.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://inwebjor.ru/uplcv?utm_term=upgrade+windows+8+to+10+free PDF link annotation
    • http://azizolace.cz/images/file/sufufomopegotoku.pdfIn PDF document text
    • https://childprotectionindia.com/lexcyberia/userfiles/files/botasulawa.pdfIn PDF document text
    • http://mictrogiang.com/userfiles/files/jufusitub.pdfIn PDF document text
    • https://bluza-shop.ru/content/File/52710398369.pdfIn PDF document text
    • https://nailseasupportgroup.com/wp-content/plugins/super-forms/uploads/php/files/193d2beff326f078ee8230c235e1d2df/57604918819.pdfIn PDF document text
    • http://aptekadc.pl/userfiles/userfile/32791943351.pdfIn PDF document text
    • http://okfilm.kr/userData/board/file/silife.pdfIn PDF document text
    • https://phm.vn/upload/files/11166134782.pdfIn PDF document text
    • http://phongthuydotho.vn/upload/files/91163849689.pdfIn PDF document text
    • https://vjlabor.pitscovn.com/uploads/Upload/files/3507305330.pdfIn PDF document text
    • https://groupunsur3.com/contents/files/21627521214.pdfIn PDF document text
    • https://xn----8sbcehyodmtf1czh.xn--p1ai/userfiles/file/megojovupuximololiwumarug.pdfIn PDF document text
    • http://cserepakciok.hu/xdata/file/81813968896.pdfIn PDF document text
    • http://pure-chiral.com/upload/files/wodasamatolemefalogiwi.pdfIn PDF document text
    • https://marlin-aquarium.ru/ckfinder/userfiles/files/58288062470.pdfIn PDF document text
    • https://textmakareknutsson.se/upload/image/lobukivalozaro.pdfIn PDF document text
    • http://atya.eu/files/file/gibume.pdfIn PDF document text
    • http://jiehuist.com/userfiles/files/77441538321.pdfIn PDF document text
    • http://www2.grupoksl.com.br/js/ckfinder/userfiles/files/jajadupodi.pdfIn PDF document text
    • http://zjgyuanhong.com/v15/Upload/file/2021982053298365.pdfIn PDF document text
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/912a527b01b89640a5b2c8aef682a4a0/wikejipitegemofek.pdfIn PDF document text
    • http://studioego.cz/userfiles/file/30358707075.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ef91d5b57b---nodeximotod.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_off0000aea7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEA7 11100 bytes
SHA-256: d983a2e8dc936f4806ec9b6b834178ccf3ae730deb323864a1c2b5e583097c2b
font_01_sfnt_off0000c88f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC88F 14332 bytes
SHA-256: 53731cc73ee973c13221907f3d96b8954be2543a83d47e45f045137e111991be
font_02_sfnt_off0000ec80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC80 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1