Malicious PDF — malware analysis report

Static analysis result for SHA-256 ea90ca4c85da41d4…

MALICIOUS

PDF

69.4 KB Created: 2021-02-18 06:53:24 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 649a73ecfd0a9d7f07e4d17688d74cbc SHA-1: 95dc30fef0bd0737063b086fa454a22060ed4d64 SHA-256: ea90ca4c85da41d4d47853ce2f3d212a81d249dc2cef3e0cc28d853d7ed0e4ce
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, identified by the PDF_SEO_LINK_FARM heuristic, pointing to various PDF files hosted on external services. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or distributing further malware through this link farm. No scripts were extracted, and the document body was heavily obfuscated, preventing a more detailed analysis of the specific lure.

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://druttle.ru/wix?keyword=reliability+engineering+pdf+ebook
    • https://zemapefim.weebly.com/uploads/1/3/4/4/134485651/4e6e971.pdf
    • http://shoop-fh.ru/sajavutigatohcmhh.pdf
    • https://cdn.sqhk.co/zuxosutuku/Txiagcd/pixel_puzzle_collection_apk.pdf
    • http://kigenavozos.iblogger.org/guide_rna_design_online.pdf
    • https://cdn.sqhk.co/terasovo/cjdhief/desert_riders_mc.pdf
    • https://cdn.sqhk.co/kasuwajavi/eiejcie/royal_oak_archery_club.pdf
    • https://dilozerekake.weebly.com/uploads/1/3/1/4/131452754/fa80e.pdf
    • https://cdn.sqhk.co/sewuvavimebi/hdgdjfy/big_red_button_meme.pdf
    • https://vuzevarezevarot.weebly.com/uploads/1/3/0/7/130740461/noluji.pdf
    • https://cdn.sqhk.co/wemorapi/fsmxvHf/draw_synonym_in_urdu.pdf
    • https://fumevixupi.weebly.com/uploads/1/3/0/7/130775707/a109e60a6b6493b.pdf
    • https://vofesoxofibebup.weebly.com/uploads/1/3/4/9/134900141/vafefowamilepinagiv.pdf
    • https://cdn.sqhk.co/japokaxe/Fifijia/amazon_goes_gold_espana.pdf
    • https://cdn.sqhk.co/gapobuzijiru/si7iijb/bushcraft_survival_skills.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c772.bin
a19803effa286b9aab2d3e1ef623cc70ec0343d05deaa66bb62a571db8cf59bf
pdf-font-stream PDF embedded font (sfnt) at offset 0xC772 5132 bytes
font_01_sfnt_off0000d8fc.bin
6a3b2cd393e8007f6293c77cd642f06b788e9b8e71d1b07f9ab94b75a834a8b3
pdf-font-stream PDF embedded font (sfnt) at offset 0xD8FC 9812 bytes
font_02_sfnt_off0000fa74.bin
ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA74 4324 bytes