Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1c271113c333028…

MALICIOUS

PDF

71.3 KB Created: 2021-09-28 00:07:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 95132b04c998b5234e047b2127792276 SHA-1: fec016f5cc65339af3533fc7a6800786826a9daa SHA-256: a1c271113c33302895aa793296b64aaa2fa6b4a7a245db8c5d36ac8188140e63
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and is identified as a link farm, with many links pointing to compromised WordPress uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and embedded links are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://synerhu.ru/uplcv?utm_term=facetime+video+not+showing PDF link annotation
    • http://unixsensor.com/uploads/files/202109101247576584.pdfIn PDF document text
    • http://zpkprzemysl.pl/ckfinder/userfiles/files/saxatiginimesazovosugasu.pdfIn PDF document text
    • http://www.toptehnik.si/images/19129433090.pdfIn PDF document text
    • https://fong-cai.com/upload/files/mufelenizoxugomi.pdfIn PDF document text
    • https://yensaovinastar.com/media/files/zisadupakek.pdfIn PDF document text
    • http://feuerwehrobrigheim.de/upload/files/84596888493.pdfIn PDF document text
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614a1c25552ab---xigiwufuz.pdfIn PDF document text
    • http://1544-7419.net/upload/fckeditor/file/jomeweritoneruligizedoliz.pdfIn PDF document text
    • https://officialbacknumber.org/editor_up/bilinekaratopotufatizule.pdfIn PDF document text
    • https://drakbera.com/ckeditor/ckfinder/userfiles/files/lelavibe.pdfIn PDF document text
    • http://investgeorgia.ge/userfiles/file/logowunejulewu.pdfIn PDF document text
    • https://minjar.mebel18.com/uploads/files/nigenetusugarex.pdfIn PDF document text
    • http://www.gleason.com.au/application/third_party/ckfinder/userfiles/files/xawisokafinuwefubos.pdfIn PDF document text
    • http://kup-vino.cz/web/ckfinder/userfiles/files/65920245841.pdfIn PDF document text
    • https://petala.gr/userfiles/file/32691878642.pdfIn PDF document text
    • http://www.agenbenangbandung.net/file/32753351235.pdfIn PDF document text
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/39068f72cc2128de462cb281678f4f6a/vejukidenube.pdfIn PDF document text
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613be82423cf4---68393248804.pdfIn PDF document text
    • https://macauroommate.com/ckfinder/userfiles/files/vonufobejumoxadiparuxeje.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_off0000b2ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2BA 10800 bytes
SHA-256: 6b4689db28230a10242482dc3bb379ba01164d8a39ca389d2df0da8b1fc09ea3
font_01_sfnt_off0000cb4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB4F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e361.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE361 17260 bytes
SHA-256: 97d38c55e23e460bd5843ed065e8082c0577ffac55513360ede7a155e09f4e5a