Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfbe5ea25e65e666…

MALICIOUS

PDF

81.9 KB Created: 2020-12-18 03:08:43 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: af081e265db8247dad65ca7843adb933 SHA-1: e8210f923c306234e307142f50f7006fac04deb9 SHA-256: cfbe5ea25e65e6662dc6510d45c39c5308ca8e955711425070b40fdcc06e9c20
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of external links, many hosted on disposable domains, indicative of a link farm or phishing operation. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, and the presence of numerous external URIs points towards an attempt to redirect users to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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
  • 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.
  • 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://trafffe.ru/strik?utm_term=easy+brown+gravy+mix+recipe PDF link annotation
    • https://sobegivi.weebly.com/uploads/1/3/4/3/134311910/656454.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489041/normal_5fb2801cc23c0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4468253/normal_5fd2784642337.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391340/normal_5f9ea0c5897e9.pdfIn PDF document text
    • https://tusidotug.weebly.com/uploads/1/3/4/4/134482214/zodurexa_viwedus_vologufo_zufijezedolexek.pdfIn PDF document text
    • https://geserani.weebly.com/uploads/1/3/4/3/134347405/5655482.pdfIn PDF document text
    • https://tixoguwod.weebly.com/uploads/1/3/4/6/134694164/xukugogijojivikamato.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388424/normal_5f9b27404386c.pdfIn PDF document text
    • https://dipejabixeg.weebly.com/uploads/1/3/4/7/134716175/3975549.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4412181/normal_5f95b1812aec9.pdfIn PDF document text
    • https://jezasowafinam.weebly.com/uploads/1/3/4/5/134530254/jakujenulikabazibi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4423442/normal_5fb273dd01061.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://static1.squarespace.com/static/5fc5dd7fbda9c57a97e032dc/t/5fcdedce8a55f2188b9b002d/1607331278547/surirewawub.pdfIn PDF document text
    • https://static1.squarespace.com/static/5fce37932ebf7d3ac6444665/t/5fd7108e0f11661d4c43915b/1607929998679/band_aid_emoji_android.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
    • https://savannah.gnu.org/projects/freefont/In PDF document text
    • http://www.gnu.org/licenses/In PDF document text
    • http://www.gnu.org/copyleft/gpl.htmlIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cf98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF98 6440 bytes
SHA-256: 2ce5a7286efefc5aae27ce1c31b3347e159d00bd30cf97f509a0b7f7d49caffb
font_01_sfnt_off0000df8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF8D 5348 bytes
SHA-256: af763f325cf7a6fcfc84e645237cf6a66f1a094cedb35ec389293eec37c8271b
font_02_sfnt_off0000f1b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1B2 10256 bytes
SHA-256: a8917e475c7e8bf7193d7aec9a87bc2d60b9b47fec3dc08e32b4e50a1e423602
font_03_sfnt_off00011500.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11500 16312 bytes
SHA-256: bf8f9ece8d9d74ce2d7a98a07ee1bb8f4056faf702b3b1702118181e85f1b939
font_04_sfnt_off00012a8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A8B 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176