Malicious PDF — malware analysis report

Static analysis result for SHA-256 81925aa708d6ffdc…

MALICIOUS

PDF

84.7 KB Created: 2021-09-15 21:02:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 7299ce3550bdb8787e1adc0857a5f42d SHA-1: 9c35dd97f187dfa3b1fae8a406b6cfd0051881f0 SHA-256: 81925aa708d6ffdc7a7adf64796d9a0fc3db70ded92f45877c651a717c67e876
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to external PDF files on potentially disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a malicious document, potentially leveraging JavaScript for obfuscation or redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://nikolalepojevic5.com/multimedia/file/vulidukiniwaxoluka.pdf In PDF document text
    • https://mannoorpally.com/uploads/file/27797218248.pdfIn PDF document text
    • http://gps-tw.com/CKEdit/upload/files/fikobifilivuvev.pdfIn PDF document text
    • http://myslizdrave.com/soubory/guresidaza.pdfIn PDF document text
    • http://1day2night.com/UserFiles/file/zufidosovamar.pdfIn PDF document text
    • http://lmnn.ru/userfiles/file/66330607975.pdfIn PDF document text
    • https://by-express.com/upfiles/editor/files/dodaliz.pdfIn PDF document text
    • https://skatrip.com/basefile/skatripcom/files/34625693271.pdfIn PDF document text
    • http://2990592.ru/ckfinder/userfiles/files/nomaxegot.pdfIn PDF document text
    • http://www.deep2001.com/images/library/File/gotaroviju.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e428ff0185---8558817740.pdfIn PDF document text
    • http://aliguoriarchitetto.eu/userfiles/files/jagugojivoposodorikaloveg.pdfIn PDF document text
    • http://tion.hu/upload/file/kikobijajimikakodi.pdfIn PDF document text
    • https://fullmagicweekend.com/ckfinder/userfiles/files/watinupopefilufedokugadav.pdfIn PDF document text
    • http://solo-reisen.com/media/images/file/wuvurari.pdfIn PDF document text
    • https://senfina.top/uploads/files/11519630558.pdfIn PDF document text
    • http://bjxbw.cn/userfiles/file/31431934909.pdfIn PDF document text
    • http://kaiyudachem.com/filespath/files/20210902175404.pdfIn PDF document text
    • https://maharajganjtimes.com/assets/ckfinder/core/connector/php/uploads/files/19364308572.pdfIn PDF document text
    • https://foundryindia.org/userfiles/file/juwatijuwujivadota.pdfIn PDF document text
    • https://taiwan-tiaya.com/upload/tiaya_official/files/lilikivodadonexowa.pdfIn PDF document text
    • http://brenna-ski.pl/userfiles/file/6177455361.pdfIn PDF document text
    • http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/7523639514252c059a18236cef0e6aa2/jezewa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+install+android+on+laptop+64+bitPDF 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_off0000e59b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE59B 10716 bytes
SHA-256: 7bdaa60c65cfb16d36a945750401eb2e1903a71063b627539bd8f0ce8abc6a52
font_01_sfnt_off0000fe24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE24 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011636.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11636 18000 bytes
SHA-256: a6a311a8ff1c45ac757681d22129a0f2e27ba002cdce81f3e055088489fd79bf