Malicious PDF — malware analysis report

Static analysis result for SHA-256 7685deedd1138a7b…

MALICIOUS

PDF

76.2 KB Created: 2021-10-09 15:46:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 1461fbaaa8900b5bf9f47c5df97df196 SHA-1: 42329c9148f19ad7375b6d22911bd8de6ef5801a SHA-256: 7685deedd1138a7b1ec091ed2d8cdc14db9faa53148be53d04c55b41e6ac7ec0
174 Risk Score

Malware Insights

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

The PDF document was flagged by ML classifiers and ClamAV as malicious, exhibiting characteristics of a phishing and trojan delivery mechanism. The presence of a 'Browser extension / update installation lure' heuristic strongly suggests a social engineering tactic to trick users into installing malicious software or providing credentials. While no scripts were directly extracted, the document's structure and embedded URLs point towards a malicious workflow, likely involving the download and execution of a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://dichvuketoansg.com/luutru/files/71398858142.pdf In PDF document text
    • https://andhimazhai.com/images/files/nutojubamiraru.pdfIn PDF document text
    • https://trouver-une-ssii.com/img/pics/files/rikewuvuwetelimofonora.pdfIn PDF document text
    • http://mrcubezpieczenia.pl/app/webroot/media/files/75866367608.pdfIn PDF document text
    • http://tageedesign.com/ssmpt/documents/file/pupogikexe.pdfIn PDF document text
    • http://associazionemillesogni.it/userfiles/files/gazukakexixikavetusoj.pdfIn PDF document text
    • http://qzgj.cn/upload/file/mologudagutoxadokesa.pdfIn PDF document text
    • https://codecs.ro/images/file/ruretewuvivoj.pdfIn PDF document text
    • https://theatresaucinema.fr/uploads/file/29593803231.pdfIn PDF document text
    • http://xn----7sbbbizu2bxaod.xn--p1ai/userfiles/file/badukoxovilu.pdfIn PDF document text
    • https://www.delaneyllc.com/ckfinder/userfiles/files/30756289151.pdfIn PDF document text
    • http://zzps.pl/userfiles/file/novapuj.pdfIn PDF document text
    • https://drlanda.hu/user/file/fubetadapefalalelone.pdfIn PDF document text
    • http://goldartline.ua/userfiles/file/solemudusujaminuwimovepoz.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/16148a92c8af26---kadobivokafogu.pdfIn PDF document text
    • https://kimcert.com/E/file/pulesotanuwedopelupulag.pdfIn PDF document text
    • http://ankaser.com/userfiles/file/taxufemivux.pdfIn PDF document text
    • http://aptekarynek.pl/zdjecia/fck/file/bulufuxebavusisewigi.pdfIn PDF document text
    • http://dui-antidote.com/images/userfiles/file/21955050924.pdfIn PDF document text
    • http://www.scsk12.org/policy/files/files/turapuvotamigujadalir.pdfIn PDF document text
    • https://biodent.ro/m4fm_files/m4news/ck-uploads-files/tinulorezawuzifit.pdfIn PDF document text
    • https://hantverkarenisandby.se/UserFiles/files/gabojepaxigexam.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=internet+download+manager+add+to+chromePDF 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_off0000c844.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC844 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e056.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE056 16512 bytes
SHA-256: 2d3a1182e573ac6e02d883dbe40254b37a22284ed83cb5b41f84b515ff6e92d0
font_02_sfnt_off00010af5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AF5 10596 bytes
SHA-256: 4dc2e935af5e8ecc2daef30febc090b67180a4ab5bfb1838b11bf1e5c3d743b2