Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b6c1c89a9f6aff2…

MALICIOUS

PDF

77.6 KB Created: 2021-09-12 02:16:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 28ab8ca3942d55b65311f16498895d25 SHA-1: db07dca12fbe12703260ff818b4adf6fb66de674 SHA-256: 4b6c1c89a9f6aff29782a6d331ea20a03f188f9be27112d746d82efa4e49b214
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as 'Pdf.Phishing.Trojan' and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with multiple URLs pointing to potentially compromised CMS upload directories or disposable hosting. The embedded URLs suggest an attempt to lure users to download further malicious content or engage in phishing activities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://didula.ru/img/file/9212611461.pdf
    • http://eptesteplelek.com/uploads/file/wikukovu.pdf
    • https://cristiandellavedova.com/wp-content/plugins/super-forms/uploads/php/files/bc85118b6c60ea2edb7677df42ce7d7c/fasuxiviwasetuko.pdf
    • http://xn--vb0b83rba554gca.kr/page_data/file/20210901062358.pdf
    • http://anapro.com/ckfinder/userfiles/files/gekura.pdf
    • http://yishiweb.com/upfiles/files/20210912_050658.pdf
    • https://fuoriscena.eu/file/47620081664.pdf
    • http://thaoduocvn.com/userfiles/image/file/17028977370.pdf
    • https://siemreaptraveltours.com/userfiles/file/gixeje.pdf
    • https://washlounge.in/ckfinder/userfiles/files/dojavi.pdf
    • https://angkaganjil.com/contents/files/fikoj.pdf
    • https://www.sexualaufklaerung-schule.ch/ck/ckfinder/userfiles/files/rigoduvupijok.pdf
    • http://dui-antidote.com/images/userfiles/file/nujosovawemufokokepujow.pdf
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/scjuuk1pdr8g5oilmjvsj28ga2/24447142878.pdf
    • http://isleford.com/filespath/files/20210909020324.pdf
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613356a0cba66---46397325276.pdf
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab2c7baa06---rilisuvuvasojexefejitu.pdf
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/161342fd672878---22619212962.pdf
    • http://emirates-offshore.com/uploads/image/file/27720033633.pdf
    • http://blekinge.boj.se/uploads/userfiles/files/68024859302.pdf
    • http://perchegouet.com/ckfinder/userfiles/files/18904090222.pdf
    • http://21cedu.com/pds/userfiles/files/57829328957.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=windows+movie+maker+2020+free+download+64+bit
    • 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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cae6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCAE6 16792 bytes
font_01_sfnt_off0000e2fd.bin
ad1fc74a4b4cd324b9698662f4dfae7a245d074de408537824f176f1ec93b9d9
pdf-font-stream PDF embedded font (sfnt) at offset 0xE2FD 11380 bytes
font_02_sfnt_off0000fdeb.bin
c0bac029ba1b901e792ec98e9ce5c25fe7913a569985181ad31b62be85c2d260
pdf-font-stream PDF embedded font (sfnt) at offset 0xFDEB 16628 bytes