Malicious PDF — malware analysis report

Static analysis result for SHA-256 35be98cf9b2b7308…

MALICIOUS

PDF

72.7 KB Created: 2021-09-15 12:06:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: e0f9479320f0b6ea04e8865bc2333e85 SHA-1: 92780363afc42f5067421509aa93de0575b70741 SHA-256: 35be98cf9b2b7308a317bf43992c353fdfcf8932704dfa31f011c48a69e9b339
134 Risk Score

Malware Insights

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

The PDF was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV detection as a phishing trojan. The presence of numerous embedded links, many pointing to potentially disposable domains, and a 'download button' lure suggests an attempt to trick the user into downloading a secondary payload. The wkhtmltopdf authoring application is not inherently malicious but can be used to generate deceptive documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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
  • 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 http://badischer-kunstverein.de/ckfinder/userfiles/files/27312369634.pdf In PDF document text
    • http://ksiclubbiz.ksiclub.org/svnprojects/DHD/Source/images/files/zejodokapupolezu.pdfIn PDF document text
    • http://deborahkay.com/ckfinder/userfiles/files/jivoxatinezuwozeju.pdfIn PDF document text
    • http://bajajsports.com/userfiles/file/696586445.pdfIn PDF document text
    • http://aeusjtu.pretty-match.com/upload/files/nijomawo.pdfIn PDF document text
    • https://alummaswaja.com/yii/sdbalikpapan/home/images/upload/files/fajolabinudut.pdfIn PDF document text
    • http://boldino-hotel.com/ckfinder/userfiles/files/lebot.pdfIn PDF document text
    • https://alsharqcc.com/userfiles/files/zubekeler.pdfIn PDF document text
    • https://szabolcsipeter.com/userfiles/file/28326200550.pdfIn PDF document text
    • https://www.milestonesmn.org/ckfinder/userfiles/files/faxebomosuzitataz.pdfIn PDF document text
    • https://mamap.in/ci/userfiles/files/74296540717.pdfIn PDF document text
    • https://damsindia.org/admin/uploads/file/1258666651.pdfIn PDF document text
    • https://dursunguney.com/userfiles/files/mezuxugoxumu.pdfIn PDF document text
    • http://halongbaycruises.org/upload/files/gukat.pdfIn PDF document text
    • http://websteravelandscaping.com/editorData/file/34085555477.pdfIn PDF document text
    • http://abpjseah.news-read.com/upload/files/lamelarinuzutodan.pdfIn PDF document text
    • https://metricgroup.it/uploads/file/lexopilago.pdfIn PDF document text
    • http://eldorautomaticgates.com/UserFiles/file/kejirigavudufukujegise.pdfIn PDF document text
    • http://kodemari.info/data/files/benebiju.pdfIn PDF document text
    • http://ilsogno-bomboniere.com/userfiles/files/15531058311.pdfIn PDF document text
    • http://pokrowce-ochronne.pl/Upload/file/2317177348.pdfIn PDF document text
    • https://kamhosting.nl/ckfinder/userfiles/files/lesin.pdfIn PDF document text
    • http://hytechplus.com/userfiles/file/lexiluwomevaredulu.pdfIn PDF document text
    • https://artinterior.bg/userfiles/file/53108885463.pdfIn PDF document text
    • https://abzesolar.com/uploads/files/vapukotefeduzuluvovuz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=methagu+full+movie+onlinePDF 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_off0000b87c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB87C 10552 bytes
SHA-256: 39c0b73b4afd09419a407a0f78b0c90b43b0560b88a4251f7565ecdfde24fad0
font_01_sfnt_off0000d064.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD064 17308 bytes
SHA-256: 7f6b9d238cd451466c981469dc5737a62dfb09d9632a8b2ecd6ea6641a3b0652
font_02_sfnt_off0000fd63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD63 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1