Malicious PDF — malware analysis report

Static analysis result for SHA-256 e31884fc7caf0900…

MALICIOUS

PDF

83.0 KB Created: 2021-09-06 11:12:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 4a6363494c9d956a83f00aa8aab9443b SHA-1: 38ac31198e46c7d5420ebf8f13f40f7c698d820c SHA-256: e31884fc7caf0900374b2ab82074f188800e9c2d07520ba5326b35e80f23e988
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://www.syria-report.com/sites/all/libraries/ckfinder/userfiles/files/mijunogosi.pdf In PDF document text
    • https://www.treehousecare.org/wp-content/plugins/formcraft/file-upload/server/content/files/16077ec7d338be---wikogaranosut.pdfIn PDF document text
    • http://topas.lt/userfiles/file/rugifuwivoxunininorigajuz.pdfIn PDF document text
    • https://estudiowebcolombia.com/ckfinder/userfiles/files/tigizuvunerizalutesabid.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/16100309bdb150---79758003103.pdfIn PDF document text
    • http://b-solutions.net/userfiles/file/bizulasasor.pdfIn PDF document text
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610a9d425b4dc---759531809.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/uc8voq5funsf67kpdql47laeo6/maridevedibu.pdfIn PDF document text
    • http://naturallabs.de/userfiles/file/81126513519.pdfIn PDF document text
    • http://yule-sign.com/upload/editor/file/20210903225035.pdfIn PDF document text
    • http://bamboomfi.com/htdocs/cljr/data/files/wiroxebemivonaxu.pdfIn PDF document text
    • https://obermeyer-modemarkt.de/upload/file/8090597419.pdfIn PDF document text
    • http://gardens-spa.com/user_pict/file/gonog.pdfIn PDF document text
    • https://www.mnspineandsport.com/wp-content/plugins/super-forms/uploads/php/files/d399305193fe608a4d556bd676e4d99d/10080952006.pdfIn PDF document text
    • http://zge-led.com/luodan/images/userfiles/file/67917980305.pdfIn PDF document text
    • http://workprohealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d0a486bb13---wekaluvisibobe.pdfIn PDF document text
    • http://ever-pioneer.com/upload/files/sunivewurenun.pdfIn PDF document text
    • https://italvaping.com/file/55336746341.pdfIn PDF document text
    • http://wxbeimei.cn/upload/ckimg/files/202108181931522493.pdfIn PDF document text
    • http://unseenadventure.com/userfiles/file/9088883469.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/160abd1d845acd---tutowutidufagononoreg.pdfIn PDF document text
    • https://techlan.pl/files/file/fomijitata.pdfIn PDF document text
    • http://vivo-mebel.ru/upload/file/zajomexob.pdfIn PDF document text
    • https://promobryansk.ru/userfiles/files/dutoj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=ferromagnetismo+paramagnetismo+y+diamagnetismo+pdfPDF link annotation
    • 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_off0000dd87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD87 17772 bytes
SHA-256: 5379d970965ff8b947b668d0317e67d86bc51c95b8f411c2d962c9ccaeec5969
font_01_sfnt_off00010af1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AF1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012308.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12308 10884 bytes
SHA-256: 5c186621809eafb58ece25400b712bfb52b5389b88aada9556812890705075e8