Malicious PDF — malware analysis report

Static analysis result for SHA-256 747ffa69bdbff783…

MALICIOUS

PDF

37.8 KB Created: 2020-04-23 03:57:20 +03:00 Authoring application: wkhtmltopdf 0.12.1.4 (via Qt 4.8.6) First seen: 2020-09-24
MD5: cacfeac73df8ecd056c7d40e536ca7c4 SHA-1: 2347651d533b468ccb5b32db9b72d4c25139ed67 SHA-256: 747ffa69bdbff783c9567ccc741372274e84a627fbccfc849bb4206e42d4f87e
136 Risk Score

Malware Insights

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

The PDF contains a large number of links to other PDF files, suggesting a link farm designed to attract traffic or distribute malware. The presence of a heuristic firing for 'LOLBin token sequence in document text' matching 'wget -nv https://download.webupd8' indicates an attempt to download external content. The ML classifier also flagged this PDF as malicious with high confidence.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

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.
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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://starrmark.net/uploads/1/3/0/3/130313363/130313363.html#blackboard+collaborate+linux PDF link annotation
    • http://jedstream.com/uploads/1/3/0/7/130775892/b0c871.pdfIn PDF document text
    • http://jerrodguillorycomedian.com/uploads/1/3/0/6/130620327/lotazujexugeg_jirog_kufibabunewogo.pdfIn PDF document text
    • http://mindcoach.poker/uploads/1/3/0/6/130620380/mapejojiroxo-rojivixe-bovugizob-nuzuw.pdfIn PDF document text
    • http://aplace4me.net/uploads/1/3/0/8/130814387/wedaviwer.pdfIn PDF document text
    • http://rubicon-customs.com/uploads/1/3/0/4/130490719/nowom_vazofinatepok.pdfIn PDF document text
    • http://relinemaintenance.com/uploads/1/3/0/6/130604699/0a05e9578d5ae.pdfIn PDF document text
    • http://local9068.org/uploads/1/3/1/4/131438622/bugofifez.pdfIn PDF document text
    • http://slantrobotics.com/uploads/1/3/0/7/130740524/81410.pdfIn PDF document text
    • http://theropesproject.org/uploads/1/3/0/7/130739015/5251064.pdfIn PDF document text
    • http://ciceroformation.com/uploads/1/3/0/5/130550814/puzak.pdfIn PDF document text
    • https://softwareIn PDF document text
    • https://download.webupd8In macro / runtime command snippet
    • http://linux..htmlIn PDF document text
    • http://downloadIn 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006b4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6B4F 8288 bytes
SHA-256: d7dc30fdfe7b9238ae675ce2933cf5621e5890b8be772da1976b3f4fdb2a4bff