Malicious PDF — malware analysis report

Static analysis result for SHA-256 37aefa91b844c890…

MALICIOUS

PDF

75.3 KB Created: 2021-09-11 17:28:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 3f9d348f1a13c340fed69c3320789745 SHA-1: cab41a8379fd4a804d7493d6c8a00ec33f5e7d95 SHA-256: 37aefa91b844c890f24da011c3cc19f1cd2dc0fcab7a207bc368bd19e777398c
126 Risk Score

Malware Insights

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

The sample is identified as a malicious PDF by ML classifiers and ClamAV. It contains numerous embedded URLs, with a heuristic specifically flagging it as a link farm on disposable hosting. The presence of a 'utm_term_redirector=True' suggests a redirection mechanism to obscure the final destination, likely a phishing or malware distribution site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://agrostroi-proekt.ru/ckfinder/userfiles/files/wotukiruwejodajisobenimi.pdf In PDF document text
    • http://tech-sub.com/userfiles/file/81645841349.pdfIn PDF document text
    • http://designpavelzapletal.cz/files/file/29847897268.pdfIn PDF document text
    • http://miskolciharsona.hu/pictures/file/nasarafu.pdfIn PDF document text
    • https://kiofruits.com/admin/uploads/files/mowefezax.pdfIn PDF document text
    • http://webs123.com/userfiles/file/28981248505.pdfIn PDF document text
    • https://tatsolarlight.com/uploads/files/bipekopujumovoxudepawux.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/16131141ccb29a---85383433445.pdfIn PDF document text
    • http://congluc.com/upload/files/19501227074.pdfIn PDF document text
    • http://nedvizhimost-v-sharm-el-sheikhe.ru/uploads/files/847295085.pdfIn PDF document text
    • http://bdsps.org/slbdavbatala/userfiles/file/52218188981.pdfIn PDF document text
    • http://24cvety.ru/upload/files/96147281380.pdfIn PDF document text
    • http://tentauto23.ru/ckfinder/userfiles/files/19071471167.pdfIn PDF document text
    • https://irish-setter-zucht.info/ckfinder/userfiles/files/93654507102.pdfIn PDF document text
    • http://sriagasthiyarastro.com/FCKeditor/userfiles/file/dumekituxidi.pdfIn PDF document text
    • https://wolfgang-photography.com/userfiles/files/41216811688.pdfIn PDF document text
    • https://demetraproject.eu/ckfinder/userfiles/files/nasaladijowirijamuxivatij.pdfIn PDF document text
    • http://zhizhencn.com/filespath/files/20210907192552.pdfIn PDF document text
    • https://thaibamboorestaurant.ca/phpsites/bard_ford/uploads/file/witelubofefimubu.pdfIn PDF document text
    • https://girisimhaber.com/uploads/file/90285401947.pdfIn PDF document text
    • http://cbcom.eu/ressource/site-image/files/5644975544.pdfIn PDF document text
    • http://www.css-jp.com/upfile/files/2021/09/03/80236568664.pdfIn PDF document text
    • http://dsfly.com/uploads/files/63405891015.pdfIn PDF document text
    • http://ssaisarang.com/ckfinder/userfiles/files/64500482503.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/2a7a88edde01f895b20ce94e285fdba9/nigukisinu.pdfIn PDF document text
    • https://flour.co.uk/ckfinder/userfiles/files/nunofovobugezujopo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=app+lock+mod+apk+downloadPDF 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_off0000c411.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC411 17380 bytes
SHA-256: 493b4f1e75e0b085ea4e96e989d665eba29c699e0935bfafe72ccbfc495d4e08
font_01_sfnt_off0000f04d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF04D 10244 bytes
SHA-256: ad40596b5cac85aec269f869cb8e7d91fc99a2ab56731880f76097279f53eddc
font_02_sfnt_off00010759.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10759 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1