Malicious PDF — malware analysis report

Static analysis result for SHA-256 7786d1c26a18422a…

MALICIOUS

PDF

74.9 KB Created: 2021-08-24 23:34:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: b876c156d935b685cd69824888ce9af4 SHA-1: 8b59bd6560e370dc96221cd766c7c0025a66eb3f SHA-256: 7786d1c26a18422a168da9e64ffcf9ebd4a9f2c6bf1b3f148cff435d2cf1838d
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm pointing to multiple compromised or disposable domains, a common tactic for phishing or distributing further malware. The ML classifier and ClamAV detection strongly indicate malicious intent. The malformed stream length heuristic suggests an attempt to hide malicious content within the PDF structure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.8645

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
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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
  • 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://nangluongvada.com/uploads/files/98453423021.pdf In PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/160792abbdf88c---1279674283.pdfIn PDF document text
    • http://lungshingcentre.com/userfiles/7100529170.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/19859bb63db861879d07546acea90522/jakoxonebetukade.pdfIn PDF document text
    • http://vom-ragnaroek.de/uploads/file/fixozuvojupigumesuni.pdfIn PDF document text
    • https://majubesar.net/contents//files/70052425880.pdfIn PDF document text
    • http://thuduchouse.vn/pics/file/xedakotaginugigegelif.pdfIn PDF document text
    • http://cs-golfclub.com/ckupload/files/75440179729.pdfIn PDF document text
    • http://leebyunghun.kr/new/upload/board/files/lisobo.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/162dd00ea0cf1c4f8ecba01e8d475ad0/bepuvedaxalewop.pdfIn PDF document text
    • http://cbafjvn.com/uploads/userfiles/file/seruwujudiginavulikego.pdfIn PDF document text
    • http://ejmk.com/ej/upload/files/5370858213.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/20e874f49e2c8aa361fe2fd8eaa8bc07/96098529468.pdfIn PDF document text
    • http://kaztelcom.kz/ckfinder/userfiles/files/67403780868.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e5fd0d09ca---piwukeburi.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606d1a71e9b1c---20991309286.pdfIn PDF document text
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b3c8563e31---91391875380.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abad581962a---43263614043.pdfIn PDF document text
    • http://tasarimak.com/ckfinder/userfiles/files/mofelelijonikefunolunez.pdfIn PDF document text
    • http://hncastlecable.com/d/files/gagavakin.pdfIn PDF document text
    • http://gachtrangtritranvinhtin.com/gachtrangtritranvinhtin/Images_upload/files/xusuxus.pdfIn PDF document text
    • https://techielingo.com/fck_uploads/files/rugolutufulizi.pdfIn PDF document text
    • http://hoanggiaphatland.com/uploads/image/files/96815305698.pdfIn PDF document text
    • http://www.mmalappeenranta.com/tiedostot/files/widumoluvodu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=nyt+spelling+answersPDF link annotation
    • 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_off0000d0bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0BB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e8d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8D2 10484 bytes
SHA-256: 14f86ad3db5fbae21e9d5762ea9bc05452b79eb791244433e7d913447cd71fb3
font_02_sfnt_off000100d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100D9 17032 bytes
SHA-256: 05ab98b7cc6bc135528845628c96929933799b238fb6d6e32257475fe4eec1a6