Malicious PDF — malware analysis report

Static analysis result for SHA-256 cef811c25c17f9a4…

MALICIOUS

PDF

73.0 KB Created: 2021-02-23 15:54:45 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 74605c39266463b8acd9b3ba5208b432 SHA-1: 2242f79908390cc15237f00383c0ca06483edcee SHA-256: cef811c25c17f9a41da0ea7d275fec9cf95b669852b424f798702af7fb28d151
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file is a PDF containing a link to a malicious URL, identified by the 'PDF_MALICIOUS_REDIRECTOR_LINK' heuristic. The ML classifier and ClamAV also flagged this file as malicious. The embedded URL, 'https://yafferge.ru/strik?utm_term=1999+chevy+silverado+brake+line+routing', suggests a phishing attempt using a seemingly innocuous topic to entice clicks. No scripts were extracted, but the presence of malicious links strongly indicates a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://yafferge.ru/strik?utm_term=1999+chevy+silverado+brake+line+routing
    • https://favadela.weebly.com/uploads/1/3/1/0/131070298/vuzofojugobigo-podewiripi-bizusexevab.pdf
    • http://mon-cmbretagne.com/army_vs_zombie_1._0._4_mod_apkgwecc.pdf
    • http://hihikane.space/bar_graphs_and_charts_worksheetsafw20.pdf
    • https://dugigoje.weebly.com/uploads/1/3/4/7/134754128/527102.pdf
    • https://pabedowilopore.weebly.com/uploads/1/3/1/1/131163579/mumarubexinoz.pdf
    • http://teaitalis.space/chinese_character_numbers_worksheetekn2z.pdf
    • https://cdn-cms.f-static.net/uploads/4477913/normal_60155a3153748.pdf
    • http://kismykeitio.best/takoruxinefaitzjc.pdf
    • https://pagowabelada.weebly.com/uploads/1/3/0/8/130874520/zedarigodex-soletixowobu.pdf
    • http://lukanovetefitef.22web.org/2013_buick_verano_parts_manual.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/rebomedug/83153233946.pdf
    • https://s3.amazonaws.com/wuzalugiseto/cassandra_db_guide.pdf
    • http://rurakudusabi.rf.gd/texto_informativo_breve_de_animales.pdf
    • http://wotonopeg.epizy.com/23482115610.pdf
    • https://s3.amazonaws.com/napisakaluja/9302057062.pdf
    • https://s3.amazonaws.com/sefabe/gugezolulifudenifexu.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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e193.bin
94e373f4b104d360664fa3688fae078cc41e1de24d14085ec0b6dc75fdf2c4cf
pdf-font-stream PDF embedded font (sfnt) at offset 0xE193 5680 bytes
font_01_sfnt_off0000f4eb.bin
38a2dc9605f9a4374308f37ce6fa968ec87417927cf4fdabe0139b64d743a308
pdf-font-stream PDF embedded font (sfnt) at offset 0xF4EB 10008 bytes