Malicious PDF — malware analysis report

Static analysis result for SHA-256 a77f496404e917e5…

MALICIOUS

PDF

69.3 KB Created: 2021-09-21 07:46:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2160d3a1a6cfd69ddb7ef3570c9039f5 SHA-1: 623137fddae8576ef80ff36c48be63565f87b66f SHA-256: a77f496404e917e50e822d8da579ceb3a8f016e48c1cef9c161ba75364570c04
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 websites or disposable hosting, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The document body is heavily obfuscated and unreadable, providing no direct content clues, but the heuristic firings and URL analysis confirm a malicious pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://queure.ru/uplcv?utm_term=thug+life+game+free+download+for+android
    • http://anadolumatbaa42.com/genelresimler/file/87777755027.pdf
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/e34ca0952e00dfcc758743f598d3bf6d/wivud.pdf
    • http://llux.vn/uploads/files/semefivav.pdf
    • https://zapret-rf.org/web/img/podborky/files/73651645932.pdf
    • http://enjoy.sk/editor_uploads/system/files/zaxolexuxofala.pdf
    • http://ingatlantv.tv/userfiles/files/baweke.pdf
    • http://museodegliarazzimarsala.com/userfiles/files/goduliwidexux.pdf
    • https://ksboutlet.com/file/files/94889467570.pdf
    • http://mcutech.net/files/putikamijod.pdf
    • https://aymsoft.us/aym_image/files/bizagosago.pdf
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/1614855782e5a7---vodude.pdf
    • https://eco-translation.ca/upload/editor/file/vojaduto.pdf
    • http://creatinglifeoptions.com/userfiles/files/86844276213.pdf
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/71f865596c6b42b9fc0f8b8899368338/83820671380.pdf
    • http://www.ciesol.com/ckfinder/userfiles/files/xariro.pdf
    • http://orthocarecentroortopedico.it/userfiles/files/35234919795.pdf
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/bf9r686jp9g3b9f3qbc1appic2/vanabarudilegilereta.pdf
    • http://www.tempshift.com/app/webroot/files/uploadimagesfile/mulixawub.pdf
    • http://kyochonbuenapark.iorderfoods.com/uploads/files/penezuxokibonon.pdf
    • http://bobmeetin.com/media/galleries/files/29177203786.pdf
    • http://stylekd.ru/files/mabojekiveli.pdf
    • http://onlinetalk.jp/app/webroot/img/fckfiles/file/4093793150.pdf
    • https://innotek.vn/uploads/news_file/15301245844.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b204.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB204 16792 bytes
font_01_sfnt_off0000ca1b.bin
39fdac3f4fac1e8fda35ebbf55a62679104da020e6bd1cbf3fd02788a2f5a966
pdf-font-stream PDF embedded font (sfnt) at offset 0xCA1B 10684 bytes
font_02_sfnt_off0000e22c.bin
f852dd394e5fed5eaed15b3d7bdb1b48595ca8e5d146d810cf474de725d451d7
pdf-font-stream PDF embedded font (sfnt) at offset 0xE22C 14976 bytes