Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1a89c1f5f38c3ad…

MALICIOUS

PDF

79.1 KB Created: 2021-11-12 18:21:09 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: ab7981138e6885906d282b7b1e4156ec SHA-1: 2a7e2c3048d91971bd636046beca47297248c9f7 SHA-256: b1a89c1f5f38c3ad11271e2b3dedf19f02261217e987303c45993d695ec96c77
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external URIs and is structured as a link farm, with many links pointing to disposable hosting. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for human readability but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 https://huntic.ru/uplcv?utm_term=combine+like+terms+meaning PDF link annotation
    • http://pawsandtiaras.com/ckfinder/userfiles/files/zojavekirozobosuzinimiril.pdfIn PDF document text
    • http://taixingchem.com/uploadfile/file/20211014155107645.pdfIn PDF document text
    • https://samsungdvmklima.com/upload/ckfinder/files/84056684909.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615f314f0adf7---10375793833.pdfIn PDF document text
    • https://illinoisfiscalpolicycouncil.org/app/webroot/userfiles/file/87830134727.pdfIn PDF document text
    • http://shiny-baby.com/fileimage/file/daboxi.pdfIn PDF document text
    • https://xn--pssa17sw71b.tw/upimages/files/sixebezulujir.pdfIn PDF document text
    • http://www.neoneophytou.com/ckfinder/userfiles/files/30027645902.pdfIn PDF document text
    • http://111-orte.de/testarea/cwsCMSlight/media/files/53518494100.pdfIn PDF document text
    • http://alanurturizm.com/rsm/files/94225195036.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files/zivonimisefosefinedodena.pdfIn PDF document text
    • https://bnbtravels.com/ckfinder/userfiles/files/3319989447.pdfIn PDF document text
    • https://ibericadearmerias.com/file/woxojafu.pdfIn PDF document text
    • http://sysquare.com/UserFiles/files/metavagimakij.pdfIn PDF document text
    • http://poney-club-romilly-aigre28.fr/userfiles/file/99787478499.pdfIn PDF document text
    • http://cybernet-ap.com/UserFiles/File/10549013918.pdfIn PDF document text
    • http://www.otevrenysklep.cz/ckfinder/userfiles/files/26482169599.pdfIn PDF document text
    • http://araonline.hu/uploads/file/letarupupoxugimofukapizit.pdfIn PDF document text
    • http://demo-jesma.shopcloud.es/ckfinder/userfiles/files/16560500627.pdfIn PDF document text
    • http://swaving-stalinrichting.nl/ckfinder/userfiles/files/14461103867.pdfIn PDF document text
    • https://optimuselearningschool.aels.edu/learning/site/images/uploadfiles/93986720749.pdfIn PDF document text
    • http://samtle.net/ckupload/files/mesowukopelumixuz.pdfIn PDF document text
    • 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_off0000cdca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDCA 10716 bytes
SHA-256: c198f0709d4e84535c508df4c1a90158ad81857dd050e6dcd8a89e85949383d3
font_01_sfnt_off0000e667.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE667 16540 bytes
SHA-256: 45015263e28dbf00792e0fa83ae0fb9123af5110209f191c00797c49350166ef
font_02_sfnt_off0000fd88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD88 18932 bytes
SHA-256: 3750c618e6cd5888197fbb6ba84ba13df6dc25755ac6c7f5f9a6303f71ed1fe4