Malicious PDF — malware analysis report

Static analysis result for SHA-256 9586dfe6c145abc8…

MALICIOUS

PDF

75.6 KB Created: 2021-03-23 18:43:55 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 933c022ba2f8a24ac355d3ac97cc91e8 SHA-1: 48d27287b456253a9d1605a973f1c9462af4ba76 SHA-256: 9586dfe6c145abc8e520de5afc4c2ae7a5675f644fb438884c9ef60f0ec5fa4a
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing or trojan threat. It contains a large number of external links, many pointing to PDF files, suggesting a link farm or SEO spam tactic. The document body, though heavily obfuscated, contains keywords related to educational worksheets, likely serving as a lure to encourage users to click on the embedded malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://kuzutuzo.ru/wix?keyword=emancipation+proclamation+worksheet+in+your+own+words
    • https://static.s123-cdn-static.com/uploads/4369506/normal_5fde05f0c64ef.pdf
    • https://nurosizakudagag.weebly.com/uploads/1/3/4/6/134699554/d183f.pdf
    • https://cdn-cms.f-static.net/uploads/4420025/normal_6026ff33791f1.pdf
    • https://gulufoge.weebly.com/uploads/1/3/0/7/130776817/596af.pdf
    • https://cdn-cms.f-static.net/uploads/4489407/normal_60394eac285ab.pdf
    • https://cdn-cms.f-static.net/uploads/4487903/normal_602420851af0d.pdf
    • https://cdn-cms.f-static.net/uploads/4452398/normal_6036b9c30645f.pdf
    • http://bugilinupapud.mygamesonline.org/lavorururuba.pdf
    • https://cdn-cms.f-static.net/uploads/4451369/normal_60301724e1d9f.pdf
    • http://fekowepiz.mywebcommunity.org/96693728123.pdf
    • https://gubuwogufulero.weebly.com/uploads/1/3/4/6/134608521/6311458.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/sitozi/jakaxameluveb.pdf
    • https://s3.amazonaws.com/wekibik/mofupenodekazowiredelogu.pdf
    • https://s3.amazonaws.com/somamere/66966868515.pdf
    • https://s3.amazonaws.com/zebarufuridorur/42911354673.pdf
    • https://s3.amazonaws.com/sitozi/velefokapalesuvedosisibe.pdf
    • https://s3.amazonaws.com/rupatojuko/29092174402.pdf
    • https://s3.amazonaws.com/besafefaf/chhaila_bihari_song.pdf
    • https://s3.amazonaws.com/befafuni/wilotarudajenojaxepek.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_off0000e999.bin
26238ea9f2d016d63113f355d4c529580f6cd721aaacbceb42335aef8c79367b
pdf-font-stream PDF embedded font (sfnt) at offset 0xE999 5528 bytes
font_01_sfnt_off0000fc50.bin
cef85d068fce1e33084b00ad16c6d42bd9c1002527e97ab2171ee707aa863b58
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC50 10716 bytes